To err is human...
An e-mail arrived this morning fresh from my boss' brain with our "thought for the day." This isn't something he does every day, just today, actually.

It said something like this. "In order to maintain our high standard of quality, please always error [emphasis mine] on the side of caution and send all materials to our proofreader before we go to print."

Sensing an opportunity to be a smartass and delighting in the irony that he committed a grammatical gaffe in an e-mail pertaining to catching just such things, I replied to his e-mail with, "Actually, it's 'err' on the side of caution, but, point taken."

Then he replied with some other smartass remark. I'm glad I have a boss with a sense of humor.