LightLane is a concept gadget that paints a bike lane around your bicycle with laser-light as you pedal through the night:

Enter LightLane, a safety concept from the clever designers at Altitude, Inc. The system projects a virtual bike lane (using lasers!) on the ground around the cyclists, providing drivers with a recognizable boundary they can easily avoid. The idea is to allow riders to take safety into their own hands, rather than leaving it to the city.