Who or whom? A clear, simple answer from a professional grammarian

John McIntyre edits and writes for the Baltimore Sun, teaches editing at Loyola University Maryland, and is a former president of the American Copy Editors Society. He has this to say regarding the who/whom dilemma:

My advice to you, if you have trouble deciding when to use who and when to use whom, just use who for both subject and object. It will simplify your life, ease your mind, and put you ahead of the game when the dictionaries finally attach obs. to whom.