Wired article on Digital Graffiti

Wired has an article up about 6 different digital graffiti projects.

PHONE TAG

Who: Troika artist group
Where: London
How: The SMS Guerrilla Projector - a Nokia cell phone attached to a miniature projector with a long-throw lens - can cast text messages more than 80 feet away onto street signs, buildings, and unsuspecting passersby; once it was even used to beam questions into people's living rooms. Troika members occasionally project a phone number - or hand it out to pedestrians on business cards - so that people can send the team suggested text messages. The artists then select phrases best suited for the location they have in mind: for example, "Where are we all going?" over a road sign, or, next to surveillance cameras, "You are being watched. CCTV monitoring."
Word: "It's a powerful way to exhibit your thoughts and make people react," says Troika member Sebastien Noel. "The effect can be as strong as the most thought-provoking kinds of graffiti."