Happy Hans wrote:
The rest of us are sure Terry Fox is sleeping peacefully. Especially those of us whom saw him run.
Those of us WHO saw him run*
Who is a subjective pronoun meaning that it works as a subject in a sentence (in this case: the people that saw him run).
Whom is in the objective case meaning it is used as an object in the sentence.
Ex.: There are many people for whom cheating like Rob's is inexcusable.