From 2008 to 2009, Simpson made several guest appearances as Lyle, a fictional intern, on The Late Show with David Letterman. During that time, he also appeared in episodes of CSI: Crime Scene Investigation, My Name is Earl, House, and Psych, and had supporting roles in the films The Invention of Lying, directed by Ricky Gervais (2009), and Date Night, with Steve Carell (2010).