A battery-powered, scale-model car with inkjet heads (or maybe marker pens?) underneath - you'd put it on your huge sheet of paper on the floor, it would zoom around a bit making sure it knew where the edges were and then it would be ready to be sent a print job from your computer (via 802.11 or Bluetooth). It would know it's location on the paper by measuring its wheel rotations or (more sophisticated) by triangulation between 802.11 base stations. Hmm - thinking about it this is very close to those setups people used to have to demonstrate the LOGO programming language - I'm not sure it's been done as a general-purpose printer though.-- hippo, Mar 11 2003 GraffitiWriter http://www.appliedautonomy.com/gw.html"...a tele-operated field programable robot which employs a custom built array of spray cans to write linear text messages on the ground at a rate of 15 kilometers per hour." [phoenix, Oct 05 2004, last modified Oct 21 2004] Or print with rubber marks from the accelerating and braking tires?Or a "Just Married" sign on the back and trailing paint cans, one of which is leaking a colored trail?-- FarmerJohn, Mar 11 2003 Trailing paint cans would be good - or how about a scale model of one of those trucks which paints the lines on the road?-- hippo, Mar 11 2003 A plotter that runs around and draws? Hehe. (+)-- Shz, Mar 11 2003 I refuse to say it, but... (link)-- phoenix, Mar 11 2003 Baked, by Jove.-- Aristotle, Mar 11 2003 random, halfbakery