It's fascinating to think that while Edison and Tesla battled over the ascendancy of AC versus DC, most of the world didn't think this electricity thing was going to take off - I mean, who was going to spend trillions of dollars rolling out great coils of copper wire to bring this thing to the masses? Nikola Tesla was thinking along the same lines, and the Serbian genius's mysterious Wardenclyffe Tower was to be an experiment in beaming electricity wirelessly across the world, eliminating the need for a wired power grid altogether. But wireless electricity has been enjoying a cautious revival in the past decade - mainly at short distance and for reasonably trivial applications like charging cell phones and other battery-powered equipment. And as Eric Giler's great ten-minute demonstration at this year's TEDGlobal shows, wireless power seems very close to breaking through into the mainstream market.

Watch the presentation below, in which Eric Giler of WiTricity wirelessly powers a TV from a distance of some 2m (6.5ft), and then proceeds to charge Nokia, Apple and T-Mobile cell phones using very compact versions of the same technology:

So while it's still baby steps for unplugged devices and charging, the idea of this magnetically resonant, safe power transmission seems set to enter the home very soon.

But as Giler points out, batteries and wires suck - they're wasteful of materials, they have a very finite life-span and they're energy-inefficient to produce. So we're left to wonder (again) what might have been, if Nikola Tesla had succeeded in completing his Wardenclyffe tower - and several others like it around the world, which would create a large enough wireless power grid to completely render batteries unnecessary. Battery-free phones, electric cars and home ... the only question would be - how could you charge people for it?