Revolution is the mashup of a cable tie and a stamp. 3D print any letter or symbol you want and clip it on your bike. The inking system lets you choose at which point to leave your message on the pavement.
Instructions for this opensource project on http://streettoolbox.com/wiki/Revolution
Tags: stamp, bike, street art, graffiti, activism, streettoolbox, thingiverse, 3d printing, ninjaflex, atom