Several nano-cars competed in the Los Angeles Auto Show's 2006 Design Challenge on Environmental Sustainability, but in the end they were beat by . . . a hummer?

This year's challenge had design studios transform the future of driving into an environmental experience, and competitors included the Volkswagen Nanospyder, which used nanotechnology to create a vehicle capable of being assembled, disassembled, and reassembled on a microscopic level, and the Acura FCX 2020 Le Mans utilizing nanotechnology in its compact fuel cell.

But the GM Hummer O2 is not the gas-guzzling behemoth we see today. Powered by a fuel cell, this Hummer "breathes" through a revolutionary phototropic body shell that produces pure oxygen throughout the lifespan of the vehicle. The algae-filled body panels transform harmful CO2 into pure oxygen that is subsequently released back into the environment.

It may be a while before you see a breathing, algae-filled Hummer on the lot at your local GM dealer, but I'll bet by 2008 every car in the Design Challenge will utilize nanotechnology. (photo GM)