This contrast has appeared sharper in recent years, as Microsoft’s Windows Vista operating system received a tepid critical response compared with Apple’s Leopard platform and as the company’s Live Web search service has slipped further behind Google’s. In addition, Microsoft’s cellphone software, Windows Mobile, looks old and creaky compared with Apple’s sleek iPhone and Google’s forthcoming Android mobile operating system.

But innovation does exist at Microsoft’s sprawling Redmond, Wash., campus. For instance, last year’s daring and radical redesign of Microsoft Office has been a critical and commercial success.

Now, there’s a sort of guerrilla team inside Microsoft designed to churn out innovative products more often and more rapidly. Called Live Labs, the unit is a small operation that aims to turn technology theories into real, Web-based products relatively quickly. It has only about 125 employees, and even that modest number is broken up into smaller teams tackling specific projects.

This week, Microsoft Live Labs is releasing its first broad consumer Web service, called Photosynth. This service turns multiple photos of a scene or site — say, an art gallery or a building — into a 3-D scene you can virtually “walk” through on the Web.

Unlike a simple 2-D panorama, which many photo programs can create from several pictures, a Photosynth creation, called a “synth,” is a virtual 3-D environment. It gives you the feeling you are in the middle of a room looking around, or circumnavigating a building or object. You can travel through a scene both laterally and vertically, and zoom in to see detailed, higher-resolution views of objects inside the synth, such as paintings on a wall.

For instance, you don’t just see a long, flat picture of Stonehenge or the Grand Canal in Venice. You are made to feel you are there, moving through these places, looking up at the sky or down at the ground, and pausing to examine more closely a particular stone, boat or building.

Such 3-D walk-through images have been around for awhile; they are used on some real-estate Web sites, for example, to show houses virtually. But Photosynth allows anyone to create them using any standard digital camera, and even using pictures you already possess that weren’t created with Photosynth in mind. You could even use photos of the same site taken by several people. The software will analyze the pictures, figure out which ones overlap and in what order, and then turn those shots that match up into a 3-D synth.

Photosynth, based on technology Microsoft acquired in 2006, is entirely free, and it’s entirely based on the Web, at photosynth.net (where it will be launched at midnight EST Thursday). At that site you can view not only your own synths, but the synths created by every other Photosynth user.

I’ve been testing this service for about a week, and while it has its flaws, I believe that Photosynth offers a dramatic new way to use your photos and to share them with others.

Photosynth works within a Web browser, using a small plug-in you install. Currently, it works only in Windows, using Microsoft’s own Internet Explorer browser or its rival, Firefox. A Macintosh version is in the works, but for now, you can’t even view others’ synths in the Mac operating system.

When Photosynth works right, the results are wonderfully satisfying. But it takes some skill to get a set of photos the service can match up well, a quality Microsoft calls being “synthy.” Ideally, portions of each slice of a 3-D scene should show up in at least three photos, with 50% overlap between them. After you upload your pictures and Photosynth does its best to make them into a 3-D scene, the service assigns them a percentage number that indicates how synthy they were.

In my tests, I tried both collections of photos I already possessed and some I snapped with Photosynth in mind. My pictures of a piazza in Verona, Italy, were only 38% synthy, while ones I took of a hotel room specifically for Photosynth use were 73% synthy.

One gripe I had was that Photosynth doesn’t tell you how synthy your pictures are until after you have uploaded them and waited until the system merges them, a process that can take a long time over a slow Internet connection. It would be much better if the service could tell you in advance how synthy the pictures are. Another objection is that Photosynth has no privacy settings. All your synths are open to viewing by everyone who uses the service.

But, overall, Photosynth is an impressive new way to view and share photos, and an encouraging sign that innovation and creativity still live in Redmond.

Find all of Walt Mossberg’s columns and videos online, free, at the All Things Digital Web site, walt.allthingsd.com. Email him at mossberg@wsj.com.

Beginning this summer, as soon as next month, wireless Internet access will arrive in the passenger cabins of some commercial U.S. airliners.

On these Internet-equipped planes, any passenger with a Wi-Fi enabled laptop — or a cellphone with Wi-Fi — will be able to do almost everything he or she could do online at home or at the office. That includes surfing the Web, using email, having instant-messenger text chats, downloading and uploading files, and streaming video and audio.

In fact, I did all these things a few days ago on a test flight using the new system, called Gogo. During the flight from San Francisco to Denver, on a small test jet, I could operate online as if I were sitting at my desk, or in a Starbucks. I used Dell (DELL) and Apple (AAPL) laptops, a BlackBerry (RIMM), a Windows Mobile phone and an iPhone to perform all the most common online tasks, while soaring over majestic mountains and glorious national parks.

I sent and received emails on Microsoft (MSFT) Outlook and Apple Mail, including messages with hefty attachments. I conducted IM chats on AOL (TWX) Instant Messenger and Google (GOOG) Talk. Using all the major Web browsers, I called up dozens of Web sites, and watched video clips on Hulu and YouTube. I downloaded photos, songs, PDF files and Microsoft Office documents. I used all the Internet functions on the iPhone, and on the Wi-Fi-equipped BlackBerry and Windows Mobile phone.

One important caveat: Gogo is a data-only system. It doesn’t allow phone calls and will block all services that allow voice conversations to be made over the Internet.

Gogo will launch on three American Airlines (AMR) routes, likely in July. The first planes to use it will be American’s 15 Boeing 767s flying between New York and Los Angeles, San Francisco and Miami. Later in the year, Gogo will be available on all of Virgin America’s small number of routes, and possibly additional American routes, if the first deployment works well. It’s supplied to the airlines by a Denver-based company called Aircell, which says it is in negotiations to offer the Gogo service on several other major U.S. airlines by next year.

The Gogo service will cost a flat fee of $12.95 for flights of three hours or longer, and $9.95 for shorter trips. You log into Gogo as you would any commercial Internet service, registering on a special Web page. Aircell plans to allow advance sign-up, so you’d only have to enter an ID and password on the plane. No add-on software, hardware or cables are required.

A few Web functions will be offered free from Gogo, including access to the American Airlines Web site, to Frommer’s online travel guides and to a limited selection of articles from The Wall Street Journal.

Gogo isn’t the first in-plane Internet service. A few years ago, Lufthansa (LHA.MU) offered a satellite-based service from Boeing (BA), mainly on over-ocean flights, but it was canceled.

The service operates at respectable, if not blazing, speeds — similar to what you’d get on a cellular broadband service or a slow home DSL line. On my test flight, download speeds varied from 266 kilobits per second to about 1.4 megabits per second, with the most typical speeds hovering between 500 and 600 kbps. Upload speeds were between 250 and 300 kbps. I found that most of the tasks I tested, except for streaming video, felt smooth and normal.

Speeds could degrade on a large plane with scores of people online simultaneously. But Aircell claims it has the technology to make my experience representative for anyone doing common tasks, such as Web surfing and email. During my test flight, eight laptops and six Wi-Fi-enabled smart phones were using the system simultaneously. All registered decent speeds, except for a couple of minutes when the plane was crossing between the zones controlled by the company’s ground-based towers.

Aircell gets Internet access to the planes through a network of 92 towers scattered across North America. These essentially are cellphone towers, carrying a high-speed cellphone data signal, except that the Aircell antennas point up, into the sky. A receiver on the underside of the aircraft picks up the signal, which is then distributed through the plane via Wi-Fi.

The companies say Gogo is safe and won’t interfere with the plane’s operation. It is government-approved, and pilots can shut the system off should they deem it necessary.

Gogo has some limitations. The service plans to allocate its capacity so that low-bandwidth activities like Web surfing and email take priority over high-bandwidth ones like streaming video. That means you may find video to be slow and halting.

And Gogo is a North American, land-based service only. It won’t work over the oceans and, for now, it won’t work on other continents.

But for U.S. travelers who want to stay connected in the air, Gogo does the job.

• Find all of Walt Mossberg’s columns and videos online, free, at the new All Things Digital Web site, http://walt.allthingsd.com. Email him at mossberg@wsj.com.

Now, there’s a new service called SugarSync that keeps your files replicated and synchronized across all your computers, whether they are Windows PCs or Macs. It even offers limited file synchronization on certain smart phones. The service is from a Silicon Valley company called Sharpcast and is available at sugarsync.com.

Not only does SugarSync place the latest version of every file you designate for syncing on all your chosen computers, but it also creates an archive of these files on a special, password-protected Web page. That way, you can access the latest version of any file even when you are at a public or borrowed computer that lacks the SugarSync software.

I have been testing SugarSync on five different computers — three Windows PCs and two Macs — as well as on a Treo smart phone. I tried syncing everything from Excel spreadsheets to Word documents, from photos to songs to PDF documents.

My verdict: While SugarSync isn’t free and has a few rough edges, it is by far the best solution I have tested to replicating and synchronizing your files across multiple computers. It really works.

Every time you change a file — say, by editing a Microsoft Word document or rotating a photo — the changes are replicated within seconds on every computer to which it has been synced and in the Web archive as well, as long as the computers are connected to the Internet.

For example, I set up SugarSync to synchronize a folder containing some Word documents. Then, I opened one of the documents on a Dell and added a sentence to it. A minute later, I opened the same file on a Mac, which was also connected to my SugarSync network. The file already had been updated on the Mac to include the change I had made on the Dell.

While SugarSync is primarily about file replication across computers, it also helps solve another nagging problem: backups. Because the files you care about most are now replicated on multiple machines in multiple places, and are stored as well in a Web archive, they are also backed up. So if one of your machines dies, you don’t lose your files. And, if you find yourself in need of a file that doesn’t exist on the computer in front of you, it can be downloaded.

SugarSync works by uploading your synchronized files to its servers, in encrypted form, and then sending them down to your computers when they change. There is a 45-day free trial that gives you 10 gigabytes of file storage. After that, you can keep the 10 gigabytes for $25 a year. There are five other storage plans, ranging from $50 a year for 30 gigabytes to $250 a year for 250 gigabytes.

The software that makes it all possible, called SugarSync Manager, is free and comes in Windows and Mac versions, as well as versions for Windows Mobile phones and certain BlackBerry models. An iPhone version is in the works, but for now, you can scan your online archive using a special SugarSync page available through the iPhone’s Web browser.

You install the manager software on any computer you wish to be part of the synchronized network. You can select different folders on different computers for syncing. All get uploaded to the Web archive, where they can be accessed at will.

You can choose which folders you wish to replicate fully on each machine. For instance, you might want your main documents folder to be replicated on every hard disk, available even when you’re offline. But, with a folder of lesser importance, you might be content to just fetch a file when you need it from the Web archive.

SugarSync creates two special folders. One, called Magic Briefcase, is always replicated on every machine’s hard disk, so you can quickly add a file to it even if you didn’t select the file’s original folder for synchronization. The other, called Web Archive, retains files in their original versions, never updating or changing them.

So, what are the rough edges I spoke about?

Well, the Mac version of SugarSync manager is still in beta, crashes occasionally and has various bugs. A final Mac version is promised later this spring. The cellphone versions can only view photos and whatever documents the phones allow, but changes you make on the phones in documents other than photos aren’t synced back to the computers or to the Web site.

In addition, SugarSync can’t synchronize Microsoft Outlook files and it can’t, say, replicate a new calendar entry or contact change across your computers. The company has shown off this capacity in public demonstrations and says it is working on adding it.

Still, SugarSync solves a real problem and does so well.

• Email me at mossberg@wsj.com. Find all my columns and videos online, free, at the new All Things Digital Web site, http://walt.allthingsd.com.