He is a fan of Major League Baseball, specifically a fan of the Boston Red Sox, as he stated on the August 12, 2006 episode of This Week In Baseball.
On a promotional tour to the UK in 2005 he appeared on MTV and was asked if he was going to see any bands while he was over there, he responded that he really wanted to see Oasis but they were sold out.
As of 2005, he became the third star of The O.C. to appear on Punk'd. He set up his co-star Adam Brody in 2004, and he appeared again on Punk'd in 2005, this time getting punk'd by Kutcher's crew members.