So, like a shark, Apple (AAPL) must keep moving. This week, it is introducing two new products designed to consolidate and increase its position as the leader in this new generation of hand-held computers. I’ve been testing both and I like them a lot, with some minor caveats.

One of the new products is a refreshed model of the iPhone itself, called the iPhone 3G S. It looks the same, but offers more speed, more memory, more battery life, and a few new features, including video recording and a better camera for still photos.

The second is OS 3.0, the third version of the iPhone’s operating system, which comes on the 3G S and also can be installed on all prior iPhones and Touches. It includes a much longer list of added features, some innovative and some long overdue catch-ups to other phones. These include such widely requested capabilities as cut, copy and paste; systemwide searching; a wider virtual keyboard; and a feature called MMS that allows users to send photos and videos directly to other phones without using email.

Apple last week also made a bold business move to complement these new products. It decided to keep making the current model, the iPhone 3G, and to slash its price by 50%, to $99. That’s an unheard-of price tag for a pocket computer of this power and versatility, and gives millions of additional consumers a reason to choose the iPhone instead of a competitor.

In my tests, both the new phone and the new operating system performed well, with a few small exceptions. I believe the two strengthen the iPhone platform, make it likely the iPhone will continue to attract scads of apps, and are good for consumers.

But I also regard these changes as more evolutionary than revolutionary, and I don’t think this latest iPhone is as compelling an upgrade for the average user as the 3G model was last year for owners of the original 2007 iPhone.

Current iPhone owners can get an improved product by merely sticking with their existing phones and upgrading to the feature-laden new operating system, which is free (it costs $10 for iPod Touch owners), rather than shelling out at least $199 for the new iPhone 3G S. And many new iPhone buyers can opt for the $99 3G model, which is not only cheaper, but also greatly improved by the new OS 3.0.

On the other hand, power users will crave the new model’s much-better performance, battery life, storage and other features. And some will want the new model because, unlike the current model, it’s capable of handling a new cellular network feature that, in the next few years, will offer double the current data speeds.

The new, free operating system is available for download starting June 17. The iPhone 3G S will go on sale June 19 for $199 for a version with 16 gigabytes of memory, and $299 for 32 gigabytes of memory. Those memory capacities are double the amounts offered on the previous model last year at the same prices, and far exceed the built-in memory on most competing smart phones.

These prices are for new U.S. customers on the AT&T network, plus current owners who are eligible for what AT&T (T) calls a “standard” upgrade. If you already own an older iPhone, you could pay $200 more to upgrade, depending on how far along you are in your two-year service contract and how much you spend monthly. But AT&T, stung by criticism in recent days, has just decided to offer the lower, new-customer prices at launch to iPhone 3G owners eligible for upgrades at any time up to Sept. 30 of this year, even if they were originally told they’d have to pay the $200 premium.

Before I detail the new features and how they worked in my tests, let me state up-front what the new iPhone and its new operating system don’t deliver. The iPhone still lacks a physical keyboard. It still can’t run more than one third-party app at a time, as the Pre does. Its otherwise excellent Web browser still can’t play videos created in Adobe’s Flash software, which is widely used on the Web. And it still isn’t available on any U.S. carrier besides AT&T.

Also, AT&T won’t enable MMS until late this summer, even though dozens of other iPhone carriers in other countries are doing so immediately. And AT&T hasn’t set a date by which it will offer tethering, a new iPhone feature that allows the device to be used as a modem for a laptop. Other carriers in other countries are allowing this right away.

Here’s a rundown of the most important new features of both the new hardware and software, and how they performed in my tests.

The iPhone 3G S

Speed: To me, this is the most important feature of the new iPhone 3G S. In fact, the “S” in the name stands for speed. During my week of testing, the new model proved dramatically snappier in every way than my iPhone 3G. Its processor is 50% faster than in the prior model, and it sports a new graphics chip.

Applications opened much more quickly. Web pages loaded far faster. The camera was ready to use almost instantly. And I never once saw the occasional, annoying iPhone behavior where you strike a key while typing and it sits there, seemingly stuck, before you can continue.

Cellular-data speeds were about the same, but in repeated testing on different Wi-Fi networks, the 3G S racked up speeds 30% to 50% faster than on the 3G running at the same time on the same networks.

Battery Life: On my 3G iPhone, I usually could make it through the day, but it was often a close call, with the battery indicator winding up in the red. By contrast, the new model did much better, never hitting the red zone and rarely requiring interim charging at the office or in the car, even though, because I was testing it, I was pounding it much harder than usual, making more voice calls, playing lots of videos and music, trying numerous apps, constantly downloading email from two accounts, and syncing two calendars over the air.

Apple claims about the same talk time for the new model as on the old, and about the same Web-surfing time over the cellular network. But it says the 3G S gets about 50% more battery life when playing videos or surfing the Internet over Wi-Fi and 25% more time — an astounding 30 hours — for continuous music playback.

Memory: With the new 32-gigabyte model, I was able to store over 3,000 songs, more than 1,600 photos, 74 videos, 67 applications, 400 emails, nearly 1,000 contacts, months of calendar data, and dozens of documents, and still have 5 gigabytes left over—more than most phones offer out of the box.

Camera: The new model’s camera has a 3 megapixel resolution, up from 2 megapixels, and has autofocus and a feature that lets you tap the screen to change the focus to an object or person in the background of a shot. It still lacks zoom or a flash, though it does better in low light. It also has a macro feature for close-up shots. In my tests, all of this worked, but I didn’t think the pictures it took were dramatically better than those on the old model, and it can’t compete with phones like Nokia’s (NOK) new $700 N97, which has a 5-megapixel camera with zoom.

Video: The new video recorder worked well, even in low light, and lets you post videos directly to YouTube, among other places. You can also trim your videos right on the phone. This all worked well, but the videos aren’t high definition, and pale in comparison to those on the latest HD model of the popular $229 Flip pocket camcorder.

Voice Control: By simply holding down the new iPhone’s home button, you can dial contacts and control music playback by uttering voice commands. The phone will even tell you which song is playing. Like most voice-recognition systems, this one isn’t perfect. But it worked most of the time.

Compass: I don’t consider this important for most users, but it did work when I was walking or driving. It can orient maps in the direction you’re heading.

Small Touches: You can optionally turn on a new battery indicator that shows a precise percentage of battery life left. The screen has a new coating that resists oil and grease from fingerprints.

Downsides: The new phone crashed on me twice during my tests. Once, the voice-control feature killed the sound on the built-in iPod, requiring a reboot. But I couldn’t replicate this problem. Another time, the phone froze while downloading a TV show. Apple blamed this on a prerelease server issue, and it didn’t happen again.

iPhone Operating System 3.0

Copy, Cut and Paste: Apple is late with this common feature, but it’s the best implementation I’ve seen on a phone. In a text page, you just double tap on a word, and it is selected with little handles around it that let you expand or contract the selected area. Then, you just click on a copy icon that pops up over the selection. To paste, you tap elsewhere in the page, or even in another app, and a paste icon pops up. Click that icon, and the selected text is pasted in. It worked well in all my tests.

The feature works a bit differently for some Web pages, where you hold down your finger over an area and it selects a whole block of text, like a paragraph, but still has the handles that allow adjusting the selection. It also allows copying and pasting photos. You can also just select a word or a section or a whole page of text and delete it. And if you want to undo a paste, just shake the phone.

Some Web pages and third-party apps don’t yet support this feature, but most do.

Search: Before, you could search only in the Contacts app. Now, there are search features in Mail, Calendar, the built-in iPod and Notes. And there is a way to search the whole phone at once. You just hit the home button, slowly, twice, and a special search screen appears. Type in any phrase, and it brings up every instance in multiple apps.

This is another catch-up feature, but it works well. For instance, when I searched for the word “Phil,” it brought up songs by Phil Collins, a note about Philadelphia, calendar items mentioning people named Phil or Phillips, emails to or from people with those names, and contacts for people named Phil or Phillips.

In email, the search function will even find messages that aren’t on your phone but that are stored on the servers of certain email services. For instance, I was able to almost instantly find emails from two years ago stored on Google’s (GOOG) Gmail.

One downside — in email, search looks for words only in email headers, not in the body of the messages.

Landscape Keyboard: In older iPods, the only built-in program that supported a wider, landscape keyboard, which is better for thumb typing, was the Web browser. Now, you can turn the phone horizontally and use a landscape keyboard in the Mail, Messages and Notes programs as well.

Find My iPhone: If you belong to Apple’s $99 a year MobileMe service, you can now locate a lost iPhone on a map on any computer, send the iPhone a message saying how to return it to you, and cause it to emit a beep, even if the sound is turned off. I tested this and it worked well. You can even remotely wipe all your data off the phone.

Voice Memos: The OS includes a Voice Memo app that lets you dictate reminders or other messages, and then edit and email them. I found it worked well.

Navigation: Another catch-up feature, turn-by-turn navigation with voice prompts, is also now supported. I tested this with a third-party app called Gokivo, and it did OK, though the developer admits to a prerelease bug I encountered.

Auto-Authentication: In the new OS, the iPhone can remember your log-in credentials for commercial Wi-Fi hotspot services, so you don’t have to enter them again and again. Unfortunately, in my tests with the AT&T Wi-Fi service, this failed repeatedly in several Starbucks (SBUX) shops. Apple blames a glitch in my prerelease phone’s SIM card.

Push Notification: To make up for its lack of multitasking, the new iPhone OS has a feature where third-party apps can notify you of new events, like a sports score, or a new invitation to an online game. I tried this with a game called TapTap Revenge, and it worked fine.

Stocks: The built-in stock application now has much more detailed data, including market cap, news headlines and price/earnings ratio for each stock.

MMS and Tethering: I couldn’t test these useful features because my tests were all done on AT&T, which hasn’t rolled them out.

Minor Touches: You can now move an icon among screens with one continuous motion, instead of stopping at each screen. And there are two more screens to house icons. You can finally synchronize Notes with your PC or Mac. You also can now maintain both calendars and contacts synced wirelessly with online services and those synced via cable with your computer. And you can play games and transfer files wirelessly over Bluetooth with other iPods or Touches that are nearby.

Bottom Line: Both the new iPhone and iPhone OS are packed with features that make a great product even better. But, for many users, the software may be enough of a boost to keep them from buying the new model.

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.