If you put your music in one of those "web storage lockers", it's always under someone else's control. Burning cd's is a good answer, if you want to re-make them every year or so. One friend of mine bought a large hard drive, about 40 G for about us$150 at the time, mounted the drive as a slave, and used it as a storage depot. In terms of longevity, digital audio tape is probably the best answer but not many people have the equipment, so let's not go there.