Soon, resting your phone on the backside of your tablet will charge your phone. It's not yet available but on the way.
At CES 2013, Fulton Innovation, a company whose mission is to commercialize new and emerging technologies, is showing wireless power technology efficiently transfers power without wires. Inductive coupling--specifially near-field resonant magnetic induction--electricity travels via magnetic fields instead of through a power cord.
The Verge covers it today, and Fulton posted this video recently on YouTube.