Has anyone checked out
Blip.fm (not to be confused with Blip.tv, which is a different company/service entirely) yet? It's a lot like Twitter, but you can actually post songs, DJ-style, for others to hear. And their database is pretty frickin' amazing. I've been finding a lot of stuff I've searched for, and some (like Mike Rep & the Quotas) is pretty damned obscure. Also, if you want your music featured there, read this:
How do I get my music to show up in the search results?
In a perfect world we would have every song from every band ever, and we’re working on that, but for now there’s a chance that your music isn’t in our database. If you have music that you would like to make available for others to blip, you can save URLs to music otherwise not hosted. First, create an account (or log in if you already have one), then click the “Settings” link in the top right corner and click “Music” (link: http://blip.fm/settings/music). From there you can enter in as many urls to songs as you would like and we’ll save them for you and they will be accessible from our search. If you are an artist or label and would like us to host your content (e.g., because your content isn’t hosted anywhere else), you can contact us at artists@blip.fm, providing your name and full contact information, as well as a list of the content you represent; requests will be considered on a case by case basis. NOTE: It’s a good idea to make sure the ID3 tags are in order, we plan to use them quite a bit.
Here's me:
http://blip.fm/kopper