We've all seen the upload your face campaigns made popular by Trailer Crashers but I haven't seem one that seamlessly integrates your face into the product so well. Check out this online campaign for HP which puts you into their ads.
The best part (well for flash nerds like me) is it'll take any photo of a face, crop, rotate and size the photo to fit the required area. Then add lip syncing, and blinks without the users needing to do anything.
Here's one I did with Rob's baby photo. Which you can see was not exactly cropped and ready to go. The results are quite good. I was able to choose 5 different elements, some of which were further customized, and then create this video.
My only complaint is that if you want users to add the videos to their blog or webpage, don't load the entire video unless the user clicks to view it.