A dentist noticed that his next patient, an elderly lady, was looking very nervous so he decided to tell her a little joke as he put on his gloves. "Do you know how they make these gloves?" he asked. "No, I don't" she replied. "Well," he spoofed, "there's a building in China with a big tank of latex and workers of all hand sizes walk up to the tank, dip in their hands, let them dry, then peel off the gloves and throw them into boxes of the right
size." She didn't crack a smile.
"Oh, well. I tried," he thought. But five minutes later, during a delicate portion of the dental procedure, she burst out laughing. "What's so funny?" he asked.
"I was just picturing how condoms are made!" Gotta watch those little old ladies!
Their minds are always working!

(I found this on another board from someone I use to chat with often...)