Making power out of houshold objects...

http://www.instructables.com/id/Miller-Penny-battery/%3Cbr%20/%3E

6 pennies can become a 1 or 2 volt battery.

(File under "Uses for coin in the distopian future.")

...of course, if you are out of pennies, potatoes may suffice.

http://latteier.com/potato/

and if all else fails, if you can channel enough people through narrow enough gates...

http://www.treehugger.com/files/2006/08/japan_ticket_gates.php