Internet Archive and The Wayback Machine

The Internet Archive was founded in 1996 with the intent of establishing an internet library. It's filled with video, sound, text, software, and archived web pages. One of the coolest features, in my opinion, is that it archives web content after web sites go down or after webmasters remove stuff. If your favorite site has disappeared (or if you would like to see content that has been removed), you might be able to find what you're looking for using The Wayback Machine, which is hosted at the Internet Archive.