I think the big ol' hole is starting to get bad press from the
granola types who end up tripping on the hole while playing
hacky sack or
something.
There is a book called "How to Shit in the Woods" that advocates smearing, burying, and/or bagging it out--depending on the terrain.
When camping, I prefer the tender caress of a clean rock or fir cone on my satisfied sphincter. None about? Leaves. In the desert at Burning Man? Hmmmm.