Ohhh and nster I sent you .01 ;-)
If possible, I would try switching from an nVidia card to an ATI card. You can get an HD5770 for ~$100 and get 150 Mhash/s from it at 110w peak.
150 Mhash/s is ~1.60/day (give or take, adjust for difficulty, etc)
Power consumption would be ~$0.28-0.34/day
It also depends on if you're on a time-of-use plan with PG&E, since they have a 50/75/100 plan for hours throughout the day, where rates are reduced (50% of normal) during off peak, and (75% of normal) during mid-peak hours.
Which then adjusts it to ~$0.19/day for a solid 24 hours of mining from the 5770.
Or, ~$1.31/day in profitability, on average of course.
BTW, bitcoinpool.com is 85% efficiency, and 0% fee mining pool.