Anything that involves somewhat of hand precision skills lol...
To name a few:
Flute (most musical instruments; you get the point)
Maybe being ambidextrous?
Knitting would work too
Etc...I always think of something that most people won't have just to stand out.
For my application last year I put that I was in the high school concert and marching bands, playing 1st chair trombone, A building and interior painter for 3 summers as my job, and an avid golfer and college basketball player. Basically anything that you do that uses your hands and eyes in conjunction with each other. The suggestions above are good examples also. I know a lot of female dental applicants I knew used to make jewelry and put that on their application as well... Good Luck!