Anagrams.

For those of you who haven't boned up on your wordplay, anagrams are words or sentences made by rearranging the letters or another word or sentence. The results are often quite mundane; in this case, though, they're quite funny. The original phrase is on the left, the anagram on the right.

Dormitory = Dirty Room

Evangelist = Evil's Agent

Desperation = A Rope Ends It

The Morse Code = Here Come Dots

Slot Machines = Cash Lost in 'em

Animosity = Is No Amity

Snooze Alarms = Alas! No More Zs

Alec Guinness = Genuine Class

Semolina = Is No Meal

The Public Art Galleries = Large Picture Halls, I Bet

A Decimal Point = I'm a Dot in Place

The Earthquakes = That Queer Shake

Eleven plus two = Twelve plus one

Contradiction = Accord not in it

And, by FAR the best one:

Mother-in-law = Woman Hitler

Credit: Garrick's Place of Stuff!