Water jug with pump: This is a life-saver. Way better than having to deal with those floppy water jug/bag things. And is easier than tipping over water jugs. Plus, this can be put anywhere and is very convenient.
Tailgate idea ~ Use a clear hanging shoe organizer for tailgating - hang it on the tent canopy rails and roll it up after the game. Easy way to see where things are and what needs refilling - and frees up the table for food! Good idea for camping too!