While I occasionally make an apostrophe error, especially when doing quick and dirty things like tweeting, I am shocked at how many professed writers make apostrophe mistakes. At this one site I recently went to, I must have seen apostrophes used in vain at least 10 times in the 15 minutes I spent there. Ouch.
Are you an apostrophe champion or slayer?
"If there's a book you really want to read, but it hasn't been written yet, then you must write it." ~ Toni Morrison