Andy Richter, who served as Conan O'Brien's "Late Night" show sidekick from 1993-2000, has signed on to be the announcer on "The Tonight Show with Conan O'Brien" when the re-consumated 11:30 p.m. NBC stalwart kicks off anew June 1. In between taking on a role rendered iconic by former "Tonight Show" announcer Ed McMahon and ankling his sidekick gig on "Late Night with Conan O'Brien" in May 2000, Richter has been involved in several comedy series.