I have no idea why this isn’t one of the most popular sites on the net. Pandora is a personalized online radio station. Not only is it really easy to use, but you don’t even need to register to get started. Right when you get to the homepage, the site asks you what artist or song you are in the mood for. From there, your personal radio station chooses music with similar styles that it thinks you might enjoy. If you don’t like a particular song, you give it a thumbs down, it shuts right off (moving on to the next song), the station apologies and promises not to play that song or others too much like it again. If you decide to register an account with Pandora, then you can save your stations and listen to them at any time. The longer you have a station, the more songs that it learns that you like or dislike, which makes sure that you never have to change the station. You can hear it for yourself here.