The Peace Corps is celebrating its 40th anniversary this week. More than seven-thousand volunteers currently serve in 76 countries around the world. President Kennedy first established the Peace Corps as a challenge to young people to spend two years serving in developing countries. But you don't have to be fresh out of college to sign up. Sixty-Seven year old Prudence Perry of Milwaukee is in the first few months of a Peace Corp assignment in Tonga, an island chain in the South Pacific. She says the most difficult aspect of daily life is the weather: