first joke contests

Well, more of a riddle (but funny). Why is doing nothing so very, very hard?
Because knowing when you're done is impossible . . .
(If you are doing nothing, when can doing nothing ever be finished? Maybe not as funny as I thought.)

A woman is taking a bath when she hears the doorbell ring. She calls, "Who is it?" The man's reply is, "Blind man." So, thinking that the blind man won't notice that she is naked, she climbs out of the tub and opens the door. The very surprised man says, "Uh, so where do you want me to put these venetian blinds?"
...OK