Yours truly is an avid cyclist who is acutely aware of how dangerous the sport can be, especially when it comes to numbnuts behind the wheel who remain forever oblivious to us rubes doing the environmentally cool thing of pedaling down the road. This danger is amped in the dark when seeing said cyclist becomes dangerville, until now. Thanks Chuck for turning me on to this.
Addendum: Wear a mirror and helmet whenever doing the deed. Both have saved my ass many times without question. :)