This is a Arduino based thingamabob that we built for my girlfriends birthday so the people who couldn't make it could still pop in via Skype and say hello without being immobilised.
The Arduino listens for serial input and activates one of the two outputs or both depending on the serial data.
Control interface is a simple html page with ajax calls to php script that sends the serial commands to Arduino using the php_serial_class.
Hardware wise it consists of Arduino controlling two 5v relays that then turn on 12V 40A car relays which in turn enable the power drills.
Oh and the power plugs for battery connections are made out of wine corks :)