Vacuum Pump/Table
From PROBOTIX :: wiki
This guy has some great videos here is one to make your own vacuum table: https://www.youtube.com/watch?v=fOrkvPF0pro
Here is a good reference on CNC Zone on this topic: http://www.cnczone.com/forums/diy-cnc-router-table-machines/3302-vacuum-table-vacuum-pump.html