There are some great sites out there that are really trying to help unsigned bands, one of which I like to think is our service. A new site that I came across today is Bands Under The Radar.
Bands Under The Radar is a site that likes to highlight bands from all over the world who are going completely unnoticed at the moment. The sites uses technology from Top Spin media to offer a great list of Mp3s on their site for a very little price. The last example is their download 100 songs for only $10.