MorphThing morphs faces: give it two people and it’ll combine them, to create a new person with the facial features of both. You can choose faces from hundreds of famous people on this site, or register to upload and morph your own pictures. And it’s all completely free!
Here’s George W. Bush and Tony Blair.
I thought I would give it a try using this picture of me and WifeGeeding
But I don’t think it worked so well: