Until a few months ago, I would have recommended that you stop to pee behind the nearest bush and at every rest stop available. But after spending nearly three weeks in a tent at 17,500 feet where nighttime temperatures slide into the single digits, I am now a fan of the GoGirl ($10; go-girl.com).
My biggest hesitation with a funnel, which more accurately directs your pee into any available repository, was missing the target= altogether and having to live in my own urine-splattered tent for the duration of the expedition. But the GoGirl, an easy-to-pack, easy-to-use device made from medical-grade silicon makes standing up, squatting down, or sitting over a Nalgene bottle to relieve yourself as pleasurable and discreet as going to the bathroom can be. When you finish, douse the GoGirl with water and whatever disinfectant you have available--I cleaned mine with Baby Wipes--put it back in its own handy plastic bag, then drive on. If reusing the GoGirl grosses you out, it's also sold in packets of three ($27).
Lead Photo: Courtesy of GoGirl