fuel cells -- just knock that phone around a bit to keep it juiced. At least that's the idea with three new concept handsets introduced by France-based ModeLabs, the same company hooking up with Levi's (to produce phones with decidedly less fancy recharging technology and more denim, we imagine). First up is the aptly named "YoYo," a puck-shaped device (pictured) designed to be worn around the neck that draws power from a combination of solar cells and the user's movement. Next up, the "U-Turn" somehow managed to eke out some electrons from the opening and closing of its keyboard, while the fitness-themed "Runaway" gets regenerated while strapped to the wrist. Of course, none of these are anywhere near production, but the folks at ModeLabs are apparently gunning to market the technology to manufacturers before too long.