Yes I'm stealing this idea right from tinymixtapes.com but I really don't care, I think it would be fun. Here's the concept; Someone posts a theme, doesn't matter what it is. Than everyone helps create a tracklist for it. You could list one song, or the whole list. Once the tracklist is finished the next person suggests one. I'll go first, I'd like a tape to help me "set the mood" when that chance arrives, but I'd also like to maintain my "indie sensibilities".
I'm thinking a lot of sigur ros and things of this nature.