Heat-charged cell phone

http://www.core77.com/blog/technology/this_just_inbox_patrick_hylands_copper_phone_uses_heat_for_power__17599.asp

This is an idea for a phone that would charge itself by using heat using heat-transmitting copper. Even just keeping it in your pocket would be good enough to keep it charged. I would love to have a phone that didn't need to be charged. It would be great not to have to worry about the battery dieing anymore. Not to mention that it would also be good for the environment.