Shameless plug, but we are doing exactly that here at http://milq.com. We are attempting to organize the world's media into collaborative playlists, which you can then subscribe to for a feed of content uniquely tailored to your personal taste. Subscribing or dismissing a playlist helps us recommend better content to you. Give it a look! :)

Why do you have the youtube player defaulting to 240p?

It should set it to highest available, or let it be an option.

I like it otherwise!

It defaulted to auto for me.

Wow, this is excellent. Very reminiscent of milq.com. Go to http://milq.com/bead/best-nba-plays-of-all-time for example and play a track to see the persistent player on the right.