I pour the water into my bottles, Camelbak and water bag. I also buy a can of Coke (which I rarely do) and El Sombroso salsa corn chips that are so good that I go back for seconds. A couple of big bottles of Newcastle beer max out my carrying capacity.
It's a treat to find good beer out here in the desert, which is often a sea of pissy commercial beer. I buy a pack of napkins too, and bungee my water bag onto the top of my front rack, which will make steering nice and heavy.