Here is one take on collaborative music play lists. Personally, I’d love to be able to share and download play lists from a site that attempted to map the play lists to the music I own. I’m sure there are people out there with similar taste and I would probably own about 90% of the music from their play lists that I would download. Then I could go to iTunes and buy what I didn’t own yet because I liked the rest of the play list. iTunes has a play list sharing feature that is close, but, unfortunately it’s play lists only like music purchased from the iTunes site even if I bought the CD separately. It would be killer if it realized that I already owned the music and let me just use those versions of the tracks.
In a week or so my team will be spending 3 days doing app building with Whidbey. Maybe I’ll explore the iTunes SDK and see if I can’t cook something up. Just one of the many project ideas I’ve been floating around.