If you are a piano player, I would recommend following Jordan Rudess’ Facebook page or his very active YouTube channel. The keyboardist of Dream Theater entered the prestigious Juilliard School of Music at age 9.
On his Facebook page, he often presents exercises and challenges for those who are wanting to perfect their craft of playing the piano.
Here in this video titled, “Jordan Finger Exercises. Give you fingers some brains,” he shows a very simple but effective challenge to work your finger coordination: