You know those displays at CC and BB for car stereos...
 

(Part 2 in a "You know those" series)

where you push a little red button and it powers up the unit next to it? They typically have 10 or more units and you simply select the one you want power to. How can I rig one of these systems up for something different? It doesn't need to be pretty because it will mainly be hidden. Anyone? Thanks.