There are plenty of services out there that offer either loose customization or full-blown playlist building. Services like Pandora, Slacker, and Jango let you enter the name of an artist or artists and listen to a stream of songs tailored specifically to your tastes. Other music sites like BoomShuffle and finetune allow you to pick the actual songs you’ll hear; once you’ve added X number of songs, your playlist is treated as a full-fledged Web radio station and you can listen to it as often as you like, pass it around the Web, and embed it on a blog or social network. Get free music.