My light company offers rebates up to $850 for upgrading to "a higher efficiency HVAC system", plus $2 rebates for compact florescent light purchases. Their program with Energy Star offers for someone to come in and assess what cost-effective home improvements can be made. I'm not sure how, but you could qualify for up to $600 toward making those changes. You can go to Energy Star's site for more details on what's available near you.
These are things I keep meaning to look into more in-depth for myself, but things are so hectic at the moment. I will keep you posted when I do. In the meantime, you should definitely check out what your companies offer. Please let me know what you find out, or if you have any other resources for such incentives.
I do know that there are tax incentives for hybrid owners. Haven't gotten mine yet, I'm sorry to say; but then again, I don't drive a lot.