Somebody linked this site on the OTH board the other day, and I'd been really intrigued by other sites similar to it before, so now I'm kind of addicted to this one. I seriously spent like two hours there the other night. lol
It's a photograph collection of an "urban explorer" - he basically finds his way into old, abandoned buildings around the world (hospitals, jails, hotels, schools, etc.) and photographs what he finds there. It's kind of crazy how much some of these places left behind when clearing out. I have no idea why I find it so fascinating, but I just think it's really cool to see. Some of it's a bit creepy, but I think that's part of the appeal...
http://www.opacity.us/