Forget your camp lead, your significant other, and that overly helpful sexy neighbour. A camelback is your best friend on the playa.
Another of those don’t leave camp without it items. A camelback, (or re-hydration pack) will do more to keep you alive and happy than any other item you bring. It’s basically a back pack rigged out with a water bladder and a hose for you to drink out of, but it extends your ability to wander around on the playa hugely. Bring it with you even on the shortest trip, you never know when the TARDIS art car is going to pull up and change your life, and you’ll want your water with you.
I refill mine when I arrive back in camp, just in case I need to run off.
Choose one with a wide mouth for easy filling and pouring ice cubes into. I also like a large volume of water, 3 litres or more, but I don’t mind hauling it. Put full bottles of pop in a backpack to see how you like the weight. More water means more freedom to explore the playa between refills, but not everyone wanders as much as I do, and if you don’t need it, why do the extra work.