Find your own hosting! When I went to sign up for MP3.com I got scared away after reading through the license agreement for 10 minutes. They can release your stuff on compilations and make videos for it, all without you getting royalties or (if I recall correctly) having your approval. Sounds like a contract with a mega label but without the cash advances!
I prefer to DIY it with my own site (actually runs on my old crap computer with a cable modem). And here's a tip for you: put in your song title the name of some well known artists who you are inspired by, or who you think your stuff sounds like, then leave Napster running, and get your friends to keep your MP3s in their shared folders. That way, you'll snag napster kids searching for (say) Paul Oakenfold who might grab your songs cause they're looking for some variety. IE:
(IF YOU LIKE Portishead, DOWNLOAD THIS) Modular Jack - Baby Blue.mp3
It may seem cheesy to do at first, but if you watch your upstream bandwidth over the course of a few days, you'll notice your stuff is getting downloaded by people who would never have typed in your (unknown) name. Shameless self promo improves your odds of being noticed.
-mj-