Stop Motion T-Shirt War.
Rhett and Link are a comedic team from North Carolina (one of my Craiglist stalking cities) and they make all kinds of videos. I hadn't seen them until this T-Shirt War video and I think it's a pretty funny idea. You can also buy the shirts so it's also one of the more successful product placement ventures I've seen in a while.
I am really interested to see how product placement in our programming continues to evolve but anyone thinking of doing it - watch videos like these for inspiration. Don't just turn the soda can logo out and smile.