All students of physics know that there's no such thing as a perpetual motion machine: to keep anything functioning it needs a constant intake of power. It all goes back to the law of conservation of energy and the give and take quality it has rendered to our universe.
But Intel thinks we just need to realize that there's a lot more energy out there in the universe. The problem is that we haven't figured out how to channel that energy where and when we need it so too much of it ends up getting wasted.
But Intel is investing heavily in distributed wireless sensors. Basically, these minute input devices will become ubiquitous and will suck in energy wherever it is present. So a cell phone dotted with such sensors could extract heat from our bodies, from the sun and from the environment in general. It could thus go on infinitely without needing to you to stop for a recharge. Buildings could tap into extra energy from cell phone towers.
Intel thinks its a natural progression from a trend of watches that power themselves off body heat and cell phones that harness solar energy. Not that such technology isn't without limiations. As someone who carries a body powered watch myself, I assure you it can occasionally die on you rather unexpectedly and need more than a few taps to sputter back to life.
The technology to draw energy in a systematic and measured manner across such distributed fashion is quite mature. A regulatory system to monitor who is taking who's energy is not quite in place and would need to precede any such technology. Stealing power directly from transmission lines is already common in the developing world. We wouldn't want the developed world to be suffering from energy wars where appliances continue to zap power away from each other.