Boy - there were a number of interesting things at this year's SIGGRAPPH, but so-called "Seam Carving" really seems to have caught people's attention. It seems to have hit upon exactly the right combination of: (1) Easy to demo, (2) Fake AI/magic (seeming) computer smarts, and (most importantly) (3) Relatively trivial to code. Still, even having read the preprints, I'm surprised at all the attention it seems to be receiving.
Video, which explains what I'm talking about (it is fun to watch in action):
And demos, for Windows, in Java, and even Flash, if you just want to try it online (the Windows version is the coolest).
Pretty clever. (And yes, thank you, I've seen it :P)