HOW many light bulb jokes does it take to alleviate poverty?British comedian Lenny Henry has chosen 100 examples of his country's incandescent humour to mark Red Nose Day on March 16, when the Comic Relief organisation encourages Britons to drop their traditional reserve and clown around in false noses to raise money for charities at home and in Africa.

Britons were asked to nominate their favourite light bulb jokes for a book edited by Henry that is being sold for $5.77 as part of utility company npower Ltd.'s contribution to Red Nose Day.

"Since light bulb jokes were developed in the late 1800s, they've become a national institution, and it's about time we celebrated them," Henry said.

He tried out the jokes on passers-by this week while standing inside a giant light bulb on Carnaby Street.

Among Henry's top three light bulb jokes: Q: How many reality TV stars does it take to change a light bulb? A: None. Their time in the spotlight is over.