At this point, I keep all of my music on a hard drive on one of my computers. I keep everything in FLAC format so it takes up approx. 180GB. I have yet to back that up, bu my plan is to get another large drive and sync the 2 drives whenever I update my music library. Also, I've been playing around with the idea of using RAID 1 to mirror the archive. Not sure yet.

The CD or even the DVD backup method is not very proactical for me since my archive is so large. I guess I'm too much of a purist to keep an mp3 achive instead!