The Mediachest website looks interesting. There are two things stopping me from joining. The first (and most important) is that several people from Harvard would have to join for it to be of any use to me (since I am not going to loan out my stuff to random people in Cambridge). The second is that I do not have a barcode scanner (oh, what I would do for a CueCat!), and therefore do not plan on entering all of my stuff in by hand, especially for random people in Cambridge.