Watch a master at work and stand in awe. Before each start Johan Santana, the Mets' ace, struts past his teammates, smacking and fist-bumping and shimmying, as if performing a dugout Macarena, personalizing shakes for each teammate while throwing fake pitches. The innovation is ongoing (his shakes often change from week to week) and the complexity staggering—Santana is a veritable Baryshnikov of the hands, a choreographer of camaraderie.
-Chris Ballard, The Metaphysical Significance, Staggering Ubiquity
and Sheer Joy of High Fives
Read this article. (For the lazy, the Santana part pulls from here.)