Yeah, tarmonkey, that is my kind of gable exhaust vent!
Look, the guy on the savenrg web site measured the temp in an attic. The attic had soffit vents and a ridge vent. Then he added those ugly dormer vents up top, for added exhaust vents, and the temp dropped 40 degrees.
I am intrigued by the idea of increasing the roof ventilation, that's all. The guy at savenrg makes a good case. He sounds believable, I don't know why he would make it up, since he says that you can buy the same dormer vents at Home Depot.
So, if there is a better way to ventilate an attic, without using a fan powered device, I am going to look into it.