it’s about time

It seems that many people don’t realize that the only time “it’s” is needed is when the words “it” and “is” (or “has”) are being contracted. (“It’s” = “It is” or “It has.” The word “its” signifies possession, and needs no apostrophe. (Nor do these words need one: yours, his, hers, theirs, and ours.) I guess the confusion stems from the fact that the apostrophe is used to show possession by a noun, as in “the flower’s petals.”

Inspired by fred.net.
Update: fred link still good. (Nov. 2013)