I was emailed about this yesterday(thanks, Joe and David Doherty), and it's something I thought the passersby here would definitely appreciate. The link comes from a site called Kotaku, and as they wrote, in "a technique called video mapping, the Macula project takes the 600-year-old Astronomical Clock on Old Town Square in Prague and transforms it into one of the most impressive things we've ever seen. See for yourself."
Quoting from the Makula website (translated from Czech):
Video mapping using current technology available in the entertainment industry, a whole new way. The main contents are the projections to cooperate with the selected object and try to break the perception perspective of the viewer. With the projector can fold and stress any shape, line or space. Evocative play of light on the physical object creates a new dimension and changing the view of the seemingly "normal thing". Everything becomes an illusion.
I think this is pretty cool stuff.