MojaGrandPrix(play with WebCam)

stolen from @makc3d, see http://makc3d.wordpress.com/2010/10/08/hough-transform-part-2/

/* How to play */
Get a pen, ruler, any banknote, etc. Steer it in front of webcam. see http://nullurban.appspot.com/moja-HOW-TO.swf


[T] - show estimator (for adjustment)
[W] - show/hide wheel
[UP/W] - auto acceleration
[Down/S] - auto reverse