Blabberize is a funny web application where you upload a picture and select the mouth and attach a sound clip and make a talking video clip of anything.
Nothing more to it. You can upload your picture or your friend’s or for that matter even your dog and make them/it talk.
Check this clip I made with a Scorpion fish singing Linkin Park’s What I’ve done! (sorry about the bad audio)
Give it a shot and if you make a funny video leave a link in the comment and I’ll check it out.