I need to find the pic but one beer truck on the ramp sighting led to inadvertent comedy. Around pushback time, the Captain announced a delayed due to the lavatory tanks being full. He said a lav service truck was on the way and would be there monetarily. As he finished the message, a Coors Light truck pulls up next to the plane. I remarked openly that the stuff going into the toilet tanks should be better than what was coming out. Got a few chuckles.