Cadbury made it big in 2008 with their Glass and a Half Full "Gorilla" video (which went viral and was then released on cinema's as a 2 minute spot across the world).
Here's the follow up:
Right now, it's only got about 2,700 views on YouTube but I think that the randomness (and the fact that it's the next thing from Cadbury) should help it go "viral" fairly quickly.
I'm a fan of the old school Chemical Brothers track but this spot might hit the 'random meter' a bit too hard. What do you think?