Go to Home Depot or Lowes and get a Y adapter for lights. You can find them in the electrical Isle with all the connections and plugs. You can hang 2 lights off one fixture or if you have room by 3 Y adapters and you can have 4 bulbs on one fixture. By doing this i have accumilated over 400 watts of actual wattage of CFL's with a minimum of sockets used.

Here is a pic of the one in my veg cab.