The Alice in Wonderland movie made me think about silent movies which are available online, a fair number of films are out of copyright now and so are freely available on Youtube or on DVD-Rs. Here is an example, 1924's Black Oxen which includes my favourite silent movie actress Clara Bow in one of her early roles.
More information about the movie can be seen here. Quite a few other silent movies are available online, of course the majority of films are lost forever. An art form quite different in some ways from the "talkies" that were to follow and with many stars who never managed to jump across the sound divide (as the wonderful film The Artist portrays). A great history of silent movies is Peter Kobel's "Silent Movies" which i recommend.