In case you hadn't heard this one....
Bono, at a U2 concert in Ireland, asked the audience for some quiet. Then in the silence, he started to slowly clap his hands.
Holding the audience in total silence, he said into the microphone, "Every time I clap my hands, a child in Africa dies."
A voice from near the front of the audience pierced the silence, "Well fookin' stop doin' it, then!"
(Not a true story, it appears, but funny nonetheless.)