Check this Kool Zone Personal Cooler. Its actually an evaporator that you can use in a car if used with an inverter from the 12V power outlet. Its less than $100, is compact (10"x11"x9"), lightweight (7.5 pounds), and can be used for camping as well!
http://www.compactappliances.com/sh...PRODUCT&iMainCat=23&iSubCat=40&iProductID=830
http://www.compactappliances.com/sh...PRODUCT&iMainCat=23&iSubCat=40&iProductID=830