SprayBot
http://www.thingiverse.com/thing:65156
http://www.thingiverse.com/thing:190016
http://www.thingiverse.com/thing:6133
http://hackaday.com/2011/11/17/double-pendulum-spray-gives-this-graffiti-bot-some-style/
http://000000book.com/apps/22
http://000000book.com/apps
http://www.piccolo.cc/
http://www.harbaum.org/till/cnc/index.shtml