Streettoolbox.com is a a collaborative platform for activists providing new ways of public expression. 
Here are 4 examples of innovative tools for activists to boost their campaigns. All are opensource, the instructions are available on streettoolbox.

OpenSquare is a £20 hack using a RC toy car and a few objects from the Pound Shop. It leaves a trail of powder on the ground following a computer controlled path. You just drop it on a square and press the “play” button.

Fade transforms any surface into a “glow in the dark” screen. You firstly coat the wall with a special transparent spray paint. After dark install your laser projector nearby. The laser draws with light and leaves an eye-catching fading trail behind. 

Flying Flyer is a sticker mounted on a drone. With this, you can fly around and stick your message on windows and walls. The more inaccessible it is, the better the chance that your message will never be removed.

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.

These are currently exhibited in London at the ShowRCA.