From wikipedia: Most switch-hitters have been right-handed throwers, though–among other exceptions–there have been the following players: Lance Berkman, Dave Collins, Doug Dascenzo, Mitch Webster, Wes Parker, Melky Cabrera, Nick Swisher, Justin Smoak, David Segui, Daniel Nava, and J. T. Snow (who, in the final years of his career, hit exclusively left-handed).