Andy was the sidekick on Late Night with Conan O'Brien. He recently (May 2000) left Late Night thought. It's obvious that he was very important to the show and especially to Conan as the whole last week focused on him, and the last show was completely devoted to him. Besides Late Night, Andy had a hilarious role in Cabin Boy ("This is how a harem girl dances"). IMDB has him playing a small role in an upcoming movie starring Richard Gere and Helen Hunt called Hamster Dance. Just kidding, it's called Dr. T and the Women.

Update, July 6, 2002: Since then Andy has continued to get small roles in movies and even his own tv show: Andy Richter Controls the Universe. This show was quite bad and was humanely put down after its first season (or less). It's beginning to look like leaving Late Night was a bad idea for Andy.