Cooking tip of the year: beer cooler sous vide APR 28 2010
The big difficulty with sous vide cooking at home is keeping the cooking temperature constant. Traditionally that has meant expensive emersion circulators with built-in heaters, although the price is down to $450 for the Sous-Vide Supreme. If only you could find something that insulated the water so that it stayed at a uniform temperature while cooking...
Fill up your beer cooler with water just a couple degrees higher than the temperature you'd like to cook your food at (to account for temperature loss when you add cold food to it), seal your food in a plastic Ziplock bag, drop it in, and close your beer cooler until your food is cooked.
Oh, and it'll work on camping trips as well (as long as you take your thermometer along).