The captian I flew with on the last trip made one kinda like that. "Ladies and gentleman, we have stopped just short of the gate and are waiting on ground personal to marshal us into the gate. We ask you to stay in your seat with your seatbelt fastened until we get the plane parked and the wheels chocked. Once we are finally secure at the gate, I will turn off the seat belt sign and give you that familiar ding that will announce it is time to race for the door."