Sure, Hollywood is doing cartwheels trying to stop piracy of movies, shutting down certain internet sites and fining those who help piracy live on, but you can still download movies legally, and for free! That is, movies that are now in the public domain and freely available to redistribute.

Public Domain Torrents has some pretty cool titles, such as Metropolis and Night of the Living Dead, while you can also choose to visit the Internet Archive: Feature Films site to browse a few more, like Nosferatu and Dressed To Kill. Not too shabby at all.

Source:
http://www.cinematical.com/2006/02/02/public-domain-movie-downloads-via-bittorrent/

Now you can download classic movies and b-movies movies for free at publicdomaintorrents.com. These movies are also in the public domain, which means that they can be a great source for footage and you can use them in your movies without any legal troubles. iPod conversions for some of the movies have already started.

Source:
http://akfilm.org