Ashton Kutcher, PDiddy, Larry King, Oprah, Ellen DeGeneres… the lists go on and on of celebrities promoting their Twitter accounts on mainstream media.  They are defying the myth that only youth use social media by heralding a call to action to have their fans follow them on Twitter.  While PDiddy and Ashton Kutcher may have the majority of their fan base in the “youth” range, clearly Oprah, Larry King, and Ellen DeGeneres’ fan base ru...