MovieMerge is an application that enables you to put a graphic over top of a QuickTime movie. It can blend any QuickTime supported image over any QuickTime supported movie.
I wrote the application because I couldn't find any cheap way of making a friend's movie that he took of his dog in portrait orientation into landscape orientation without distorting the movie. And then I needed to figure out what to do with the "ears". That's where the overlay of the image came in.