This is a problem with battery powered cars. There is a similar problem with ethanol--it takes lots of energy to make the fuel, so you get little savings.
However, one benefit of the Prius and other green initiatives is to create a competitive market for green technology. Already you are getting better batteries, and the fact that people have demonstrated that they'll spend extra for a prius shows there's a market, promoting investment capital.
So it's not all bad.
Further, the Hummer is way worse than other non-hybrids. Buy the most fuel-efficient gas engine you can--save on gas, and save the world. Hummer's are bad, m'kay. Unless they're the other sort of hummer...
