I never saw or heard of kids peeing outside until I saw a kid do it on Supernanny. The kid refused to use the toilet so his mom took him outside the house until he found a spot- this was out in broad daylight in plain view of neighbors. It was like he was a dog! The nanny was appalled and so was I!
In an emergency or camping...no big deal.
I'm not really understanding why anyone would "go" outdoors, on their property when there is a toilet right inside??!!