The Big Picture
A portable digital audio player sets your music free so you can easily mix and match songs in any order and take the tunes with you. MP3 players use one of two storage mediums: hard drive or flash memory. Hard-drive players offer the greatest amount of storage space but tend to be larger and more susceptible to damage due to the fragile nature of hard disks. For the most part, flash-memory models hold a more limited number of songs, but their lack of moving parts makes them more durable than hard-drive players.
Nearly all MP3 players require that you have a reasonably modern PC with a free USB 1.1 or 2.0 port. Your songs will load much more quickly with the latter. As you begin creating your music collection on the computer, you may want to upgrade your hard drive to be able to store more files.
Specialized MP3 players are not the only devices you can buy to listen to your music: You can now get mobile telephones, thumb drives, digital cameras, personal digital assistants, and car stereos that can store and play back MP3 music files. Even many pocket-size voice memo recorders can also record and play back MP3 files. But a word to the wise: Dedicated MP3 players usually sound better and often have more user-friendly controls than hybrid units, although devices like the Apple iPhone are beginning to wear this assumption down.
Storage: The greater the storage capacity, the more songs you can take with you. Hard-drive-based players hold the most--currently, the highest capacity we've tested is 80GB (which can accommodate about 20,000 MP3 songs ripped at 128 kilobits per second). The latest (and most expensive) flash-based players we've tested can hold up to 8GB of music (about 2000 MP3 songs ripped at 128 kbps).
File management: MP3 files include ID3 tags, metadata embedded within each song file that provides artist name, song title, and album name information to the player. Working with this data, a player can organize the files for you, though each does so in its own way. Most players have a built-in LCD screen; look for one that shows the information you use most.
Transfer speed/port type: Downloading 5GB of songs all at once from your PC using a USB 1.1 interface can take all night. Almost all new players employ the much faster USB 2.0; but if speed is important, ensure that your player of choice supports the faster standard before you buy.
Software: All players come with software and drivers that allow you to download songs to them from a PC. Some units work well only with their included software, while others work with a variety of music programs. Before buying, always be sure your favorite jukebox software will work with your player of choice.
File type support: All digital audio players can play MP3 files, but your music may not be recorded in that file format. If you use media files encoded in the proprietary Windows Media file format (.wma) or the open-source Ogg Vorbis format (.ogg), your media player will be able to play those files only if it has appropriate support built in. Check the player's specs, either on the box or on the manufacturer's Web site, if file format support is important to you. And even if your player doesn't support your preferred format out of the box, many manufacturers provide downloadable updates to the player's firmware, some of which may add support for other formats.
Music service compatibility: Online music stores offer users with a broadband connection a fast, easy, and legal way to build their digital audio collections. However, not all players work with all stores. For example, Apple's ubiquitous iPod line works well only with the iTunes Music Store. Similarly, online music subscription services (such as Rhapsody) that let you "rent" music for your portable audio player work well only with specific players that carry Microsoft's Plays For Sure logo. If you have a favorite online music source, make sure that it works with your player of choice.