I've seen this effect at the Magic Kingdom in Disney World (they also do it at Disneyland) and thought it was cool, but some of these examples Mashable put together are even more impressive. My favorite of the bunch is the projection on the Kharkov State Building in the Ukraine (above).
Link
http://www.youtube.com/watch?v=eCgV2g8gOQ0
mines the one with the spider :-]
Thanks for the post