The one about the sex survey...

A woman was walking down the street when she was stopped by a man who was carrying out a survey.

"Excuse me, Madam. We're doing a survey on peoples' attitudes towards sex."

"Really!" said the woman smiling.

"Could you please tell me what you think of sex on the television?"

"Well," replied the woman, "I think it's extremely uncomfortable, especially when you've got a vase stuck up your ass!"