There's been no shortage of gadgets and proposals to make charging up our gadgets easier, but what if you didn't have to charge them up at all? That's the gist of a new approach to the power problem from researches at MIT, which proposes portables get juiced up from the airwaves. The idea is to exploit the physics of resonance, the same concept that governs how musical instruments vibrate. The MIT system takes advantage the resonances of electromagnetic radiation, in particular objects with "long-lived" resonances. When you apply energy to one of these objects — say, a specially designed copper wire — it can create "tails" of energy that can be transferred to another object — say, your cell phone — with the same resonant frequency. Energy that doesn't get transferred is simply reabsorbed, making the process efficient.
Besides a few stabs at induction, there hasn't been much progress in the wireless-power field since Nikola Tesla tried to build a power-broadcasting tower at the turn of the last century. Good to see the MIT guys picking up the ball, though considering they haven't even built a prototype yet, gadgets you don't need to plug in are probably still a long way off.