So I went to all electronics yesterday afternoon and picked up a http://www.allelectronics.com/make-a-store/item/LPS-3G/12V-LIGHTED-PUSHBUTTON-2-GREEN-LENS//1.html.
I managed to find this about the button:
http://www.ultimarc.com/controldiags.html - Diagram
http://www.ultimarc.com/ultralux.html - Possible Product link
It looks like this buton can be controlled by a Pacdrive USB output driver board: http://www.ultimarc.com/pacdrive.html
Is there any way I can wire this up to my Arduino Duemilanove?