I've been designing and prototyping a cooling system for my DSLR and I found these cheap thermostats on fleabay that might interest the average DIYer. $13 for a 12v thermostat with a sensor. should be good for Dew straps and coolers.
I've bought one to give it a go, there's a lot of talk on home brew forums about them so I decided to see how it goes with my TEC 'Coldfinger'. Stand by for a review