Nokia phone never needs charging

Using an idea first posited by Nikola Tesla 100 years ago, Nokia has developed a cell phone that never needs charging.

Using ambient radio waves bouncing all around us, the phone can collect up to 5 milliwatts; not enough to make a call, but enough to charge the phone when it's not in use.
Nokia scientists hope to push that 50 milliwatts in the near future, and expect to have a commercially available version ready in five years.