LipDub.in

A lip dub is a type of video that combines lip synching and audio dubbing to make a music video. It is made by filming individuals or a group of people lip synching while listening to a song or any recorded audio then dubbing over it in post editing with the original audio of the song. [...] Often, they look like simple music videos, although many involve a lot of preparation and are well produced.

http://en.wikipedia.org/wiki/Lip_dub

LipDub.in is a catalog of that type videos all over the world. You can comment it (with your facebook account) and share with others.
Every day we update our country ranking, which shows how many (facebook) likes you give to videos created in your country.