Too bad my submission to Paizo's RPG Superstar 2010 competition, the portable latrine, didn't make it to Round 2. The item below, released under the OGL, is superficially similar, and is what I used in my home game as part of "The Coils of Set".
Feather tokenconveniently conveyable cesspit
Aura Strong conjuration; CL 12th
Slot ; Price 400 gp; Weight
Like any feather token, this wondrous item has a special power to suit a specific need, and can only be used once. Often created to assist military logistics, the conveniently conveyable cesspit aids in the quick construction of sanitary latrines and toilets. When cast onto a solid, nonliving, material surface on which the user is standing, it creates a hole or pit no more than 10 feet wide and 10 feet deep. This pit is fitted with a wooden toilet seat on the side adjacent to the user.
Requirements Craft Wondrous item, major creation, move earth, disintegrate; Cost 200 gp