I have a Teknic Jacket, fully perfed Leather, works here for me as long as I'm not sitting at a stop light, but over 90 deg and I'd have to go mesh. The way this summer is shaping up, I might buy one anyway.
FYI while we're on the topic of venting, I found Vented Leather pants (Frank Thomas) at Cycle Gear. Fully perfed, so you get some air flow on the legs, but for those of you that ride at highway speeds, still the full protection of dead cow. I like 'em so far, but they run small, I wear an 8/10 now and had to buy 12's.