Normally, when someone says a celebrity is looking jacked or buff, it's either a joke or a comment from someone using a REALLY broad definition of jacked. That being said, if any of you say Sean Penn on the Viva la Bam prank war episode, there's no question he's looking pretty **** swole for a guy his age. His arms were genuinely muscular, vascular and solid...i can say I was shocked, but there was little denying that the guy is legitimately muscular, or at least was at the time the episode was filmed.