Have you heard of a site called Pandora? It’s worth a look. Pandora effectively lets you create your personal online radio station which plays music tailored to appeal to your music preferences. By asking you what artists/songs you like, it then matches the music style to artists of a similar vein and then plays a mix of these online.
Where this gets really exciting is that you can integrate it into a website to add to the level of personalisation and customisation available to a user. Blogs, discussion boards, uploading photos and videos and contributing content are fairly typical community elements these days. Personalise radio content is one way to set a website apart.