MP3 players -- technically, digital-music players, although almost all of them are used mainly to play songs saved in the popular MP3 format -- come in three sizes: tiny, big and really big.
Tiny MP3 players use flash memory, with storage capacities that generally go from 128 to 512 megabytes, enough for two to eight hours of listening. They're extremely compact and quite affordable, but in terms of dollars per megabyte, they're actually the worst value in town. These players are best for people who want to rock out while they work out.
"Big" MP3 players still easily slip into a shirt pocket. Models such as Apple's iPod mini use miniature hard drives to store from one to five gigabytes' worth of music -- plenty to keep you entertained for a week or more. That capacity is not, however, enough to carry around most people's entire music collections.
Really big MP3 players are only slightly larger than the iPod mini and its ilk, but they do employ slightly bigger hard drives that store from 20 to 60 gigabytes of music. A player like this can hold every song you own, and still have enough room to act as a roomy external hard drive for your computer. If you don't need to take one jogging, this size is a good bet.
(If you're totally hard up for cash but still want to carry around a lot of music -- and you own a computer with a CD burner -- buy a portable CD player that can read MP3 files saved on data CDs.)
If you've started to buy music at sites that sell songs as copy-restricted downloads, that will further limit your choice: The files sold at Apple's iTunes Music Store can be played only on Apple's iPods, while those sold at stores that rely on Microsoft's Windows Media Audio format -- for example, Wal-Mart, Napster and MSN Music -- work only in non-Apple players that support a format called WMA (two are listed below).
Many people who buy MP3 players realize that they've accumulated more music on their computer's hard drive than in the living room's CD rack. But how to get that music from the computer to the stereo speakers without trailing wires throughout the house? The answer is to get a wireless media receiver, a small box that relies on WiFi networking to relay songs -- and Web radio broadcasts -- from your computer to your stereo.
Here, again, your choice may be determined by where you download. If you buy at iTunes, get Apple's AirPort Express. If you use iTunes the program, not iTunes the store -- or if you've bought songs from WMA-format stores -- get the Roku SoundBridge. And if neither applies -- that is, your collection is all MP3s managed by some non-Apple program -- get SlimDevices' Squeezebox.
-- Rob Pegoraro
Recommended in earlier reviews:
Music players: Apple iPod mini ($249) and iPod ($299, $399), Rio Carbon ($249), Creative Zen Touch ($250).
Wireless media receivers: Apple AirPort Express ($129), Roku SoundBridge M1000 ($250), SlimDevices Squeezebox Wireless ($279).