http://solarcooking.org/plans.htm
Soda bottle pasteurizer and solar chimney dehydrator as well.
The tire one looks nice, but I think it will have to wait until I'm up the hill to use it--gets to 150oF but then I run out of sun.
Don't think I can download the cob one in powerpoint.
Thanks to Sassy for this link to African Solar Cookers (do not try this in the Arctic).
http://www.scienceinafrica.co.za/3cooker.htm