We waste a lot of kinetic energy when we walk from place to place throughout the day. Some of that kinetic energy can be harnessed and used to charge personal electronic devices such as mobile phones, personal game consoles, music players, etc..
The motion of the legs and feet can be used to move a conductor across a magnetic field to generate electricity. The generated electricity can be stored in batteries. The batteries are connected to inductors in the pockets of the pants.
The personal electronic devices, that have inductors connected to their power supply, can receive the energy, transmitted by the inductors in the pants pocket, and charge their battery with the received energy, when one of these personal devices is placed in the charging pocket of the pants.