Oh. Wow. You’re probably familiar with IMDB (the Internet Movie Database), which is a great reference source for pretty much every movie ever made.
Well now there’s another rather nice site: The Internet Movie Script Database (IMSDb). Loads and loads of movie scripts online for your enjoyment. There seems to be a mix of original scripts, drafts and transcripts, and the formatting isn’t pretty in many cases, but who cares? Great for checking those lines you want to quote from whatever your favourite movie happens to be.
Found the link on the always useful Jeffrey Zeldman Presents The Daily Report, proving that not only does he write good books and the like, he also finds good links.