[off-topic] I feel very fortunate that my utility bills are about half of yours - no doubt your climate is a big factor.
I replaced my ancient refrigerator with a very efficient one and I also replaced most of my light bulbs with CFCs. I noticed an immediate impact on my electric bill!
It seems my electric bill has dropped about 25%. I'm sure I could do better though! I think I need to plug some of my 'phantom power' leaks.
I also got a new furnace with a programmable thermostat last summer. I haven't seen too much of a difference with the gas bill, but I tend to run the furnace more than I should.
My house is somewhat shaded from the sun and it is typically very damp and chilly year round. Hmm, maybe the house is haunted? 
I have 23 recessed ceiling spotlights... they provide fantastic illumination but use so much electricity at 100 watts each. I suppose I will replace those too, but am dubious about dimmable flourescent spotlights. I'm still getting used to the color temperature of flourescent bulbs. Everyone looks like they have jaundice. 
I would dearly love to install solar panels, but even with all the hefty rebates it would still cost me around $40k...
Soubasse32