No Pam, not "anywhere." I thought this thread applied to when you are cycling and no real toilet is available. I wouldn't drop my pants in downtown Boston! It seems like people are freaked out or grossed out by porta potties and hold it in, so they don't have to use them. Around here they put porta potties out on every school playground and play fields in April and leave them up until October or so, and that works out well. Even small towns in the hinterlands have a school.
Zen, I have been in that position. Once I was hiking in a local conservation area with DH and friends. It was winter. I had to go really badly and there was no place to hide, with all of the foliage gone. I found partial privacy behind a small rock, but I had to say "don't look."
lph, my older son recently told me that when he was 13, he was caught peeing in the bushes outside of the synagogue, by the rabbi.
Glad I didn't know that back then. Not sure why he didn't use the bathroom!