At first I didn't think this was really Crave-related, but I've been seeing it on so many blogs these days--Popular Science, Gizmodo, Notcot.org--that I figured, "Hey, what the hell, if everybody else is posting about it, we might as well too." Basically, a group called the Graffiti Research Lab has built (excuse me, the cool term is "hacked") a projector that can use lasers to put any kind of "tagging" on a large building or wall. It's called the "LASERTAG," which is some kind of acronym, but the Graffiti Research Lab doesn't seem to explain its derivative. While right now it's being touted as a form of next-generation graffiti, I can see this being used for everything from giant advertisements to really pricey party decor.
The Graffiti Research Lab has made this an open-source project and all the details are available on its Web site. So, what are you waiting for? Get to it! I recommend that you project a Mooninite on some massive building in Boston. I hear they love that stuff over there.
UPDATE: Thanks to Crave reader "CanadianAvenger" for clearing this up--"LASER" stands for "Light Amplification by the Stimulated Emission of Radiation." "Tag" is just "tag." The formal name of the project is, consequently, "LASER Tag."