Try posting it on MP3. They have a way to do that. Dial up MP3.com and they give instructions.  It is best if you have several songs, and a mini-CD of sorts. They give you a decent % of each song of yours that people download, and it's great promo for your music. Many bands have launched careers that way.

Another site is the one Dan used for his GREAT DB labels. (get some..I did).  It's called Cafepress.com and they take independent music as well. 

Finally there's another site, and I posted this some time ago, that will not only feature your work, and allow others to download, but will actually REVIEW your stuff and give comments.  I am blanking on it now, but will repost in a few minutes with the name.

Perhaps, and I'm not suggesting that he should, but Dan might be able to allow some of us musicians to attach/post snippets of our MP3's to this site?  I asked him about this at one time. I don't know if it's feasible, but Dan might have some thoughts about this.

Happy Songwriting,

Gene