The ultimate "Sit-Stay!"
(all my dog's obedience trainer had to do to break her sit was walk by and ask, "Hey! Want a cookie?" Dog jumps up, "Don't mind if I do. Can I jump up and get it?")
That's why she does agility and not obedience. If I can get her across the start line and the finish line, it doesn't matter what happens before or after . . .