If I had a quadcopter I would be tempted to play pranks on my partner by making it appear at the most inconvenient of moments; like when he's mowing the lawn or waking up with a cruel hangover. But truth be told this would be most helpful in sending notes to communicate with people in nearby homes next time a tropical cyclone rips through our area blocking access to roads causing full loss of power for 3 weeks (a common occurrence up this neck of the woods.) The possibilities as to what good could come from a marvellous contraption like this are just endless!