Cowon O2

Video playback on the O2's 4.3-inch screen is smooth and sharp, with the right amount of brightness and color balance. The 480-by-272-pixel screen isn't as impressive as the A3's 800-by-400-pixel display (or the gorgeous 800-by-600-pixel screen found on the Archos 5), but video on the O2 looks great anyway.

The O2's audio quality and support are as impressive as its video output. The unit's audio player supports AC3, Apple Lossless, FLAC, G.726, Monkey Audio, MPEG-1 Layer 1/2/3, MusePack, Ogg FLAC, Ogg Vorbis, PCM, True Audio, WavPack, and WMA. In our PC World Test Center's sound tests, the O2 had a signal-to-noise ratio average (the higher the number, the cleaner the sound) of 85 db--higher than some of the top-ranked players on our chart. The O2 has some great sound-enhancement features too, like a 10-band equalizer and settings for 3D sound quality. In my hands-on tests, audio sounded crisp, with no detectable static or distortion. The included earbuds don't do the sound justice, however, and they were a bit too large to fit comfortably my ears.

Despite its excellent audio and video quality, the O2 has a major drawback: It doesn't support DRM-protected music and video files. As a result you won't be able to watch WMVs from Amazon or Cinema Now or listen to protected AACs from iTunes or WMVs from certain subscription-based music stores.

Compared to the bulky A3, the O2 is positively svelte. Measuring 4.7 inches by 2.9 inches by 0.7 inch, the O2 is slim enough to fit in your jacket or pants pocket. And weighing in at 7.2 ounces, it is significantly lighter than either the 9-ounce A3 or the 8.8-ounce Archos 5.

The O2's 4.3-inch touch screen improves on the A3's 4-inch screen. And whereas the A3 carries several navigational controls, the O2 is controlled almost entirely by touch (the exceptions are a volume rocker on the top spine and a hold/power switch on the right spine).

Despite its slim size, the O2 isn't suitable for one-handed operation. To view video comfortably, you must either hold it in two hands or place it on top of a tabletop. Unfortunately, because the screen is prone to glare in brightly lit environments, you must angle it correctly for an optimum viewing experience; thankfully, the O2's stylus doubles as a kickstand. Another small but noticeable drawback I discovered was that the O2 gets a bit warm in hand.

The O2's interface is clean, easy-to-follow, and very responsive. Icons are well spaced for easy browsing with your fingertips. The main screen has five options: video, music, pictures, documents, and recent files. Hitting the arrow at the bottom of the screen takes you to less-frequently used features, such as a timer, a voice recorder, and a file browser; tapping the top arrow takes you to different settings options.

Unfortunately, the rest of the O2's interface isn't as sparse. Entries for different media files appear very closely together, listed in a small font, which makes selecting the correct file more difficult than you might expect. If you have large fingers or find yourself frequently hitting the wrong file, you'll appreciate the included stylus.

Cowon still doesn't support ID3 file tagging. Instead files on the O2 are organized in accordance with an archaic file-tree system, as they are on the A3. If you're accustomed to browsing files by album or genre, you may find the Cowon system frustrating. You must manually organize your collection on your PC through Windows Explorer or a similar file management program before syncing to the device.

The O2 also has a voice recorder, a timer, a calculator, a notepad, a text reader and a photo viewer that supports JPEG, PNG, TIFF, and raw images. Later this month, Cowon will release an open-source, Linux-based software developer kit for the O2, so more applications for the O2 should be available soon.

Though it may not have Internet browsing capabilities or much in the way of advanced features, the O2 is a solid portable media player. Thanks to its support for a wide range of file types, you'll spend less time trying to convert videos from one format to another and more time actually watching them.