This would be pretty cool to play with.
The simple explanation is that it’s a cellphone paired to a mac using proprietary software, custom scripting and graphics, and then the results are displayed through a projector connected to the computer. The whole system is mobile and with the right projector/beamer, quite bright.
[Source: TXTual Healing]
Previous posts on geek graffiti:
Laser Graffiti
Light Graffiti