if you replace all your incadescent lighting with equal wattage cfl...

a $100.00 light bill turns into a $26.00 light bill.... in a month.....
need more light? even if you double your current wattages of incadecsent  and install cfl, doubed of your old  incadecent  your new light bill is still reduced 50%.

GE 26 Watt Energy Smart CFL - 6 ... $15.23

Sylvania 29490 23-Watt CFL Mini Twist 6 pack, Soft White
Buy new: $18.99

GE 13-Watt Energy SmartTM - 8 Pa... $7.90