The word "free" here has more than one meaning: all these sites will store your music without charging you for it. So you can use all these sites to free your music as well. I would like to mention that without the help of Stig Venaas, who graciously offered to put up space for the first Free Music Archive where people can deposit and access soundfiles, this idea wouldn't have taken off. Since then, I've found out that there are plenty of other servers on the Internet which are also offering to put up soundfiles (some of them actually work from a tape or CD source!). This is a small attempt at cataloguing them.
Most of these are bands and organisations that endorse and support the Free Music idea (or a similar one), either implicitly or explicitly (or have criticised it explicitly). If a link isn't present, it means that the link was broken, but the listing was kept. If you wish to be included on (or taken off of) this list, please let me@ram.org know. Also, consider joining the Free Music mailing list, the Free Music Ring, or go to a random site in the Free Music ring.