Overheard at a fly-in for old flyers (Operation Propeller) a couple of years ago.
"G-XX request clearance for take off"
TWR- "Hold where you until You are cleared. There is a wheelchair close to to the edge of the active"
"G-XX Roger that Tower, number one after departing wheelchair?"
TWR - "Sorry about that XX, The wheelchair is non radio, so I can't get him to expidite!"