Yep. I think there's a couple of solutions out there. EyeToy has provided this in a few titles IIRC though I haven't seen it yet. They can match up certain parts of an image as a head though I'm not sure how they deal with background and lighting. You'd really need to take the picture from some decent flat lighting, otherwise you'll get your living-room lighting baked onto your face! Again, this is something that someone should have tried already with EyeToy, but I've never met such a person yet. I think there's a football game at least that allows this (and not being FIFA or PES, won't be a popular footy title) and someone must have tried various objects like cups and bananas to see what the system makes of it.
The next-gen version of the softare should do a 3D scan and create geometry for any shape!