Don't confuse this multitalented juvenile performer with the awkward adolescents he plays on screen. Off-camera, the self-possessed Sullivan is an accomplished pianist and composer, an avid volunteer and an Ivy League student. With his curly locks and memorably goofy smile, Sullivan began appearing in commercials as a toddler and graduated to TV guest spots at age 8. In 2000, he landed a recurring role on Malcolm in the Middle as one of the title character's crew of outcasts. The next year he signed on to the popular kids' sketch-comedy series All That, on which he showcased his musical talent and knack for accents. When the series ended in 2005, Sullivan snagged a role on the irreverent family sitcom The War at Home, as the geekiest of a trio of unruly kids.