Cycle your way out of traffic jams and high fuel costs-without breaking a sweat. Simply slide a canister of gasoline into your water-bottle holder, clip a throttle to your handlebars, and swap your front wheel for the Wheel, designed by Denver-based RevoPower (revopower.com). The Wheel's hub holds a 23cc, two-stroke internal combustion engine and a superthin gear train; less than three inches thick, it all fits between the prongs of your bike's front fork. Start pedaling and squeeze the throttle, and the engine kicks in, rotating the wheel around its fixed axle and boosting your power. Let the throttle go, and you can keep pedaling as usual. Just remember two things: Bring your driver's license (the engine may trigger regulations in some states), and don't drink from the water bottle.