If you've got the space, keep 'em as WAVs as well, then copy them to multiple hard-disks! ;)

That's a good idea, actually. Hard drives are so cheap these days you could buy a 200gb external and just keep it disconnected from the PC to avoid corruption from virii and just hook it up when you need some tracks. Keep decent quality mp3s or lossless mp4s for common use. -paul