Engineers from the Italian Institute of Technology taught a robot arm how to flip pancakes. The robot mastered the skill through kinesthetic learning, repeated movement. I think it’s very endearing, especially when the robot misses. From the project page:
After 50 trials, the robot learns that the first part of the task requires a stiff behavior to throw the pancake in the air, while the second part requires the hand to be compliant in order to catch the pancake without having it bounced off the pan.
Programming-by-demonstration (Thanks, Ken Goldberg!)