GrammarMan

I probably shouldn't write this one, but I can't help myself. I have a thing about the use of the King's English. My top pet peeve is the extraneous apostrophe between "it" and "s". I feel so strongly about it, I even made a special shirt to be grammar man at the office Halloween 2005.
It's simple really. "Its" is inherently possessive. "It's" is a contraction for "It is".

Enough said. Happy writing.