I'm going to try and cover this sort of thing more. Here's a pretty quality trailer mash-up which does something so simple that it seems nobody's done it before: dubbing. It works well. Then again it really isn't much of a stretch since the clips are from The Great Muppet Caper which was a heist movie itself.
Speaking of mash-ups, I've seen what purports to be the first mash-up feature made (a title that belongs to All This and World War II) called One Flew Over the Dead Poets Nest. It's an awkward title, but it's a mash-up of Cuckoo's nest and Dead Poet's Society. Though mash-up isn't the right word. I'll put the review up in a few weeks when I get the time.