I was shopping at BJ's last night and was pushing one of their big red shopping carts around the store. The carts are metal, with a plastic semi-circle attached to the top of the handle, leaving the metal on the bottom of the handle exposed.
A couple of times I felt something strange on the finger tips on my left hand so I (carefully) slid my hand along the underside of the handle to see if there something sharp under there. It was completely smooth.
I continued walking around the store and continued to feel the strange sensation every few steps, eventually realizing that it felt like I was being shocked.
I paid close attention to the position of my hands and found that if I wrapped my hands around the handle in a normal fashion, but moved my finger tips so that they were very close to, but not touching, the metal underside of the handle, I would get a static electricity shock every few steps.
It didn't hurt, but it was not a pleasant feeling.