"...use a second controller to help friends in games."
I remeber playing Mario Kart in college and one of my buddies got his wireless controller from upstairs and put it on the same channel as mine. Everytime I went to take a corner or make a critical maneuver he would move the opposite direction and send me off a cliff or into a shell. He really did and excellent job of "helping" me.
Hopefully this will enable this sort of "helping" for people to make memories. (Clearly this has stuck with me for 20 years).