VINYL RECORDINGS Nearly 30 years after gaining global status as a must-have gizmo, Sony ( SNE) announced last month that it was retiring its Walkman -- a cassette tape-based music player that has long collected dust behind more popular MP3 players such as the Apple iPod. But while mix tapes may have gone to that great technological dust heap, vinyl recordings continue to thrive -- relatively speaking. Although LPs, introduced 72 years ago, no longer command even a fraction of the sales for which they once accounted, they and the turntables to play them have defied extinction. Two particular audiences can take credit for the death row reprieve: audiophiles and DJs. For the former, vinyl albums are still considered the best of the mainstream audio formats, producing a resonating depth that comparably tinny MP3s, compressed for minimal file size, can't match and CDs don't try to. The latter group, the DJs, gravitates to the round plastic slabs in their pursuit of deep bass and the ability to scratch tracks. Thanks to such bands as the Beastie Boys, Spoon, U2, Radiohead and Pearl Jam, an even more diverse consumer base is dropping the needle, gobbling up albums at independent retailers. According to Nielsen SoundScan, last year's sales for vinyl recordings, 2.5 million units, represented a rise of 33%. Impressive, perhaps, but even more so when you factor in an 89% spike between 2007 and 2008.