Maybe you saw it in the November issue of Four Wheeler magazine (pg 68). Pretty cool idea (very spendy). I like the concept.
It's a truck box with a solar panel on top, and inverter and battery inside with power outlets and other items as options. Their Web site isn't very good so if you can see the article you'll learn a lot more and see it installed with some options.

Web site: http://www.voltabox.com/options.html