One Space or Two?

After reading a thought provoking and informative post by my clever and intelligent cousin (in-law) Cheri about grammatical errors and pet peeves with word/phrase usage, I have been informed that my lifelong habit of typing TWO spaces at the end of a sentence is no longer "industry standard." This article told me how continuing to use two spaces will provide rivers of white space that are distracting and dangerous to the overall look and feel of documents and web information. I feel like my world has been turned upside down.

**Did you know the new rule?
**What pet peeves do you have (e.g. the incorrect usage of "your" and "you're") when it comes to grammar and punctuation?