Jamendo, a free application released earlier this summer gives you streaming access to more than 21,000 free music albums and over 200,000 tracks. Jamendo is the top site in the world for free and legal music downloads, with all music made available under the Creative Commons licenses. This video gives a good overview of the application. The service offers five categories of music: Electro, Instrumental, Jazz, Lounge, and Pop.
Last FM works very similar to Pandora Radio by allowing you to create a custom radio station based on the music style of your favorite band. When you start the app you are given the option of creating your own custom library or going with Last FM’s recommendations. To create a custom library you have to sign up for a free account on their Web site.