The flight attendant asks a cannibal in First Class: "Would you like to see the menu?"
And the cannibal responds: "No. Can I see the passenger list? Thank you!"

A linguistics professor was lecturing his class one day.
'In English', he said, 'A double negative forms a positive. In some languages, though, such as Russian, a double negative is still a negative.
However, there is no language wherein a double positive can form a negative.'
A loud voice from the back of the room piped up, 'Yeah, right.'

Two lawyers arrive at the pub and ordered a couple of drinks. They then take sandwiches from their briefcases and began to eat.
Seeing this, the angry publican approaches them and says, 'Excuse me, but you cannot eat your own sandwiches in here!
The two look at each other, shrug and exchange sandwiches.