>An informed discussion and/or pointers to 12v solar panel stuff would
>be interesting.  Now that summer is here I'd love to implement a solar
>powered ventilation system.  Anyone seen such?
>

I've seen one that fits in the window, just wind up snugly and it extracts 
the hot air. <$30. Try a marine store for similiar but better quality for 
hatches.  
The local car/hardware store sells a 12v solar charger that plugs into the 
cigar lighter for trickle charging/topping up, about $40.  tim s.