make a beautiful visual google battle machine called ikwin.
this was done in a hackerscamp for the picnic08 congres in amsterdam. building time was one week, with three people.
the arduino's were used to control the height and buttons of the lifts and give some feedback in the form of a moving arrow and bell.
I'm very proud of my hacked together height-meter, based on the winding mechanism of a vacuum cleaner and a opto-coupler. A wire is connected to the platform of the lift and gets extracted from the winch. the generated pulses are counted by the arduino until a serial sended amount is reached.
the name of two persons is fetched with the help of a personal rfid tag, connected to a user profile. those names are googled and the resulting pagecount is converted to a height with a log function.
a mac controls the arduino's
more info here:http://www.mediamatic.net/page/52953/en