[aarthidhar]

If buttons on the mobile phone dial pad are made of piezoelectric material, they will deform when we press them. The resulting electrical voltage from mechanical deformation can be stored and used for charging the mobile phone.

Reward: One such.

[Tansis]

I dont believe "Piezo Power" would be enough run a cell phone directly let alone charge the battery, however I do like the idea of a hand powered telephone and cant help but think of those little dynamo flashlights that you squeeze rapidly in the palm of your hand.

[najr]

The body itself generates a great deal of heat and electrostatic charge. These could be harnessed somehow (say, in garments with a fine mesh through them) to recharge phones, mp3 players and any other portable devices.