I know I should be doing other things, but I saw this: http://www.youtube.com/watch?v=4_4POEtLd_4
.. I made one (sorry, no video) and it was just as easy and fun as on the video :)
So I wondered.. how would it be like if the angle of the bristles could be altered, then you could steer!
So I made some tests yesterday, and this turns out to be quite fun.