J.M.
It didn't happen to me much... People I knew were allowed to touch my belly, so I don't count them. I did have a few strangers, but most of them were polite enough to ask permission first, which I gave. Hey, if somebody wants to feel a miracle, why not let them? :)
although... I have always been really uncomfortable about touching other baby bumps, even people I know...
My all-time favorite experience though, was the little gay Mexican who came to my work. I was 8 months along, and this flamboyantly gay, short, petite Mexican guy came through my line. He sees my belly, and starts doing that tiny-hop-in-place-really-fast-hand-clapping move that is typically seen by teenage girls at a Justin Beiber concert, and says "OOOOH! Are we having a BABY?!?!? Can I touch it?!?!?" While rubbing my belly, he asks if I am having a boy or a girl... When I told him I was having a girl, he says, "Ooooh, she's gonna be a DIVA!" (complete with hand flip on the diva part...)
He was soo entertaining! lol. It just made my night. :)