All Things Digital

In the hyper-competitive world of consumer electronics, it’s highly unusual for one branded product to dominate its market for years on end. Yet, that’s what Apple’s iPod media player, now approaching its sixth anniversary, has managed to do. One reason is that it has been reinvented continuously.

The latest iPod reinvention expands the line from three models to four, priced from $79 to $399, with capacities ranging from one gigabyte (roughly 240 songs) to 160 gigabytes (up to 40,000 songs.) And that doesn’t count the iPhone, Apple’s much-hyped cellphone, which also includes a full-blown iPod.

I’ve been testing the newest member of the iPod family, the big-screen iPod Touch. It’s a close cousin to the iPhone that connects to the Internet via Wi-Fi wireless networking and replaces the famous iPod click wheel with a touch screen. It starts at $299, $100 less than the iPhone but with the same eight-gigabyte capacity. There’s also a 16-gigabyte iPod Touch for $399.

Like earlier iPods, the Touch is elegant and capable, and works smoothly with Apple’s free iTunes software for Windows and Macintosh PCs, as well as with its computer-based online iTunes Store, which sells far more downloaded songs and TV shows than any other legal outlet.

Not only that, but the Touch introduces a mobile version of the iTunes store. It’s called the iTunes Wi-Fi Music Store, and it allows you to buy, right on the iPod, any of six million songs for the same price you’d pay on a computer. This portable store will soon be made available on the iPhone as well.

For all its beauty and functionality, the Touch has some quirks and downsides. It’s the first iPod model I’ve ever tested that fell significantly short, in my tests, of Apple’s battery-life claims. It’s also the first iPod that lacks any physical buttons for controlling music playback.

The Touch looks, at first glance, like an iPhone that can’t make phone calls. It’s a handsome, thin, black rectangle with a huge 3.5-inch screen — the same size and resolution as the iPhone’s gorgeous screen. But the Touch is even thinner, and a bit shorter.

Like the iPhone, the Touch has just one button on its face, a Home button, which takes you to the main menu, a series of beautiful square icons. And, like the iPhone, the Touch has an on/off button along the top edge. Most everything else is controlled by Apple’s new “multitouch” touch screen interface, which includes a virtual keyboard for text entry.

But unlike the iPhone, the Touch lacks volume-control buttons and a button on its earbuds for pausing or skipping songs. So you have to play, pause and skip songs by touching the screen. This is made easier by a feature the iPhone lacks (so far): If you double-click the home button, music controls appear on the screen, even if the screen is turned off. Still, you can’t control your Touch by touch when you’re listening to music with the device in your pocket or purse.

In my tests, music and video playback went perfectly, and so did viewing photos. The Wi-Fi functions, including the Web browser, a YouTube video viewer and the new mobile store, also worked perfectly.

The Touch is missing some Internet-oriented features from the iPhone that would work well over Wi-Fi. It lacks the iPhone’s email, mapping, stock tracking and weather programs. But its keyboard has a feature the iPhone lacks: As on a BlackBerry, you can insert a period by double-clicking the space bar.

Apple says the Touch was meant mainly to present typical iPod features, not to replicate the iPhone, and it included the Web browser only so users could get onto Wi-Fi to use the mobile music store in certain places that required a log-in screen.

But it seems ridiculous to me to sell a powerful device with Wi-Fi and a huge screen, and to leave out things like an email program, even though you can use Web-based email programs. I assume Apple was concerned that the less costly Touch might compete too much with the iPhone if it had these features. In fact, if somebody can jam a voice-over-Internet capability into the iPod Touch, it might be more of a threat to the iPhone, which is tethered to a single cellphone carrier, AT&T.

The company claims that the Touch can play music for up to 22 hours and video for up to five hours on a single battery charge, even with Wi-Fi turned on. But in my tests, using factory settings, music playback lasted just under 17 hours and video playback lasted just over four hours. Nearly every other iPod I’ve tested, including the new Nano, handily beat Apple’s battery claims.

Also, some early iPod Touch units have had defective screens, where images appeared too dark. Apple says this problem affected a small number of units and is being remedied. My two test units displayed beautiful images.

Despite these downsides, the Touch is a great media player, and the iPod remains the best end-to-end portable solution for playing and purchasing music and video.

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.