I disagree; the Hummer is an evolution of a design that was pretty well worked out around the time of WW2. The Prius uses technology that wasn't used on a wide scale in an automotive application until the introduction of the Prius, and wasn't even introduced by a major manufacturer prior to GM's EV-1.
For my money, were I buying a new car with environmental consciousness in mind (and, as I stated before, I couldn't justify buying a new car on environmental grounds unless my current ride was well and truly completely worn out) I would be looking at something like a Volkswagen TDI. VW has been building Diesels far longer than hybrids have been around, and VW has a known track record for longevity.
nate