Back in September I was coming home from a vacation in England and I was flying into SFO on UA (747). We were coming in for landing and I think we were about 80-100 feet of the ground and we started to pull back up quickly. Everybody on board was laughing. Pilots came on and said a plane pulled out on the runway. SFO is a sharp take off to begin with, so aborting a landing there isn't fun. It just sucked because I think everybody by that time was ready to get off the plane.