Cowell does Simpsons for free

British pop mogul Simon Cowell is such a huge fan of The Simpsons he guest-starred on the TV sitcom for free.

The American Idol judge is notorious for commanding vast sums for television appearances, but refused payment when the show's creator Matt Groening asked him to play a nursery school admissions officer who insults toddler applicants.

An insider says: "He was just happy to be involved and was grinning ear to ear when he arrived at the studios.

"The artists got him down to a tee. He is wearing high-waisted trousers and a tight-fitting T-shirt."