Okay, I've stooped to reading ads. A United Technologies (Otis, Carrier, etc.) ad illustrates in detail the contours of a "zero net energy" building. There's nothing far out about it—and buildings today consume perhaps 40% of our energy.
I'm not conned by the ad—it just succinctly captured a ton of stuff I've been reading, and a ton of stuff underway in the green building "movement." Working on energy reduction in built environments is certainly on the prospective Obama stimulus list. But is it high enough on that list? Massive improvements can be made with proven technologies, far closer at hand than hydrogen cars or a national network of car battery recharging facilities. (And maybe the price of corn would fall in the process—thus saving starving people from bonehead Washington policies.)