Arcade washing machine!
http://www.designboom.com/weblog/cat/8/view/16814/lee-wei-chen-arcade-washing-machine.html
"to use the machine, players are required to put three pound coins into the washer which in turn dispenses three lives.
this also turns the appliance on. if a player fails to progress beyond a particular level without losing their lives,
the washing machine responds by refusing to move onto the next stage of its cycle, and hence the player needs to add more money. "
http://www.designboom.com/weblog/cat/8/view/16814/lee-wei-chen-arcade-washing-machine.html
"to use the machine, players are required to put three pound coins into the washer which in turn dispenses three lives.
this also turns the appliance on. if a player fails to progress beyond a particular level without losing their lives,
the washing machine responds by refusing to move onto the next stage of its cycle, and hence the player needs to add more money. "