A lecture about English
A linguistics professor was lecturing to his English 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 voice from the back of the room piped up, "Yeah, right."

Animals go to Heaven
A cat and a mouse died on the same day and went up to Heaven. At the top they met God and he asked them 'How do you like it so far?'

The mouse replied 'It's great, but can I get a pair of roller skates?' God said 'Sure', and he gave him a pair of roller skates.

The next day God saw the cat and asked him 'How do you like it up here so far?' and the cat replied 'Great, I didn't know you had meals on wheels up here!'