A specific technology of using fuel cells has just been patented by RIM and describes the working of fuel cell assembly. For this, you need a cell phone that has a printed circuit board, a keyboard and a also at least one contact that is responsive to the keyboard. The fuel cell assembly is sandwiched between the keyboard and the printed circuit.
The channels in the keys of the keyboard are responsible for ventilating the fuel cell. This PCB will be formed on the fuel cell and helps in keeping the size under control. The users themselves can initiate the fuel cell assembly as described by claims through a metallic plunger on at least one key that would fit through a hole in the fuel cell.
At the moment no more details are available about how the fuel tank. For that we just might have to wait a bit more.