SeeWhatYouShare.com is site about files that were found on P2P networks.
It features many files (mostly personal documents) that people are sharing on P2P networks, probably without knowing about it.
The personal documents that are found there are quite scary to have floating around the Internet, although the site does cover up any names and personal information so you don't have to worry about your personal stuff ending up on the site (just on the P2P networks).
I'm going to double check my computers to see that I'm not sharing anything that I don't know about...