One of the big things holding back your favorite gadget makers from slimming down your cell phone, PDA, or MP3 player to the extreme is the battery. No matter what your gadget poison is, it needs power, and if you want your toy even smaller (and to not need a recharge every 5 minutes) there need to be some pretty significant advances in battery technology. Luckily, a bunch of German scientists have thought about this issue a lot more than you and me. Fraunhofer Institute researchers have been developing thin, flexible batteries that can mold around the guts of future gadgets, which should allow the current trend of ever-shrinking gizmos to continue for a while. The technology could also be used in conjunction with solar power to allow, for example, a cell phone to run on standby without using any battery power whatsoever. They've even created a concept phone, pictured above, in order to mock you and make you think this technology is right around the corner. Not quite. So enjoy the picture, and keep wishing for a solar cell phone.