On sardine-can flight I was on a few years ago, we pulled up "almost" to the gate (I think most pax couldn't tell we were not all the way up yet), seat belt sign still on, and about 3/4 of the pax started getting up. Not 15 seconds later the plane surges forward just a few feet and stops. Nothing too violent, but enough to scare the crap out of those who got up. Then they shut down and turn off the seat belt sign. To this day I wonder if the pilot did it intentionally. Kind of like the "Far Side" cartoon with pilot-induced turbulence...
Jeff