Troika makes SMS guerrilla text message projector
Link: SCI FI Tech.
You could definitely have a lot of fun with one of these… pictures on the SCI FI Tech blog linked above.
The SMS Guerrilla Projector is a one-off device made by Troika Art and Design in London. Operating under the bat-signal principle, the projector shoots a text message onto whatever surface you point it at, letting you paste your own personal messages on road signs, movie screens  even some innocent schlub’s backside. Keep it clean, kids. The mischievous device also has a cell phone built into the handle, enabling you to dial in your clever slogans from afar.