Just madness, no links -- forgive my overworked state, I promise I'll have more later this week.
I suggest you spend Monday messing around with the Bookseller Wiki. Actually, you can only change it if you're an ABA member, but the accumulated knowledge (and they only just unveiled it), is fascinating. Especially the info on the order of kids' book series like Warriors -- I don't think that information is available anywhere else.
What's your favorite example of information sharing?