3 nuns die and go to heaven. St Peter meets them at the gate and says there's been a change of plan. As they have dedicated their whole lives to God he wants to reward them by sending them back to Earth as the person of their choice for 6 months.
The first nun says "I want to be Madonna" then swiftly vanishes in a puff of smoke.
The second nun says "I want to be Marlene Dietrich" then also vanishes in a puff of smoke.
The third nun says "I want to be Sarah Pippeleeny" but nothing happens. St Peter franticly thumbs through his clip board for the name but can't find anything. He says to the nun, "Who was that again?". "Sarah Pippeleeny" the nun replies. "I can't seem to find her" replies St Peter. "Here" says the nun, and hands him a newspaper cutting. St Peter reads the article and says, "It's not Sarah Pippeleeny."
"It says Laid by 10,000 men in 6 months - Sahara Pipeline!"