The result, the engineers report, is a robot 100 times more sensitive than a human finger.
The super-accurate USB-inserting skills seen above (the robot got the plug in 34 out of 36 times) didn't actually involve any rotating: The researchers hung the plug in the correct orientation, so the robot just had to lower it into its outlet.
But the researchers told Discover Magazine that this would actually be much easier than the task of finding the outlet in the first place. The outlet only tolerated about a millimeter of error, so the robot hand had to be incredibly precise. In tests, the robot was only given a GelSight sensor on one finger pad. But with one on each side, it would have no trouble feeling the embossed symbols that distinguish a USB cord -- and rotating as needed.
Realistically, the researchers aren't going to explore the possibility of creating personal USB pluggers for all of us. The robot's ability to plug with accuracy will probably lend itself to more practical applications, such as lining up and inserting screws and bolts.