I’ve been considering adding a new feature to this blog in addition to my leading geek posts: The Grammar Geek. I’ll post about my pet peeves. If my readers hate this, I’ll make it go away.
Very little in this world drives me as crazy as making plurals with apostrophes (in second place is probably NOT using apostrophes where they’re necessary). Here’s the general rule for apostrophes:
Apostrophes are used when letters are dropped or (rarely) for typographical reasons. There are three cases:
- Possessive nouns (this is historical–possessives were once formed by adding -es to the ends of nouns. When the “e” stopped being pronounced, the dropped “e” was replaced by the apostrophe, making the plural -‘s. Offhand, I don’t quite know what’s up with the possessive of plural nouns, but I think it has to do with the French (no, really, see here).)
- Contractions
- Plurals of lower case letters (“mind your p’s and q’s” (amusingly, blogger spell check wants me to change this to Ps and Qs. Note that there is no apostrophe for upper case letters–this means acronyms! (more amusingly, Firefox spell check wants me to change those to P’s and Q’s–which is wrong!!)))
Please note that, except for the third case (which has exactly twenty-six uses), NEVER MAKE A PLURAL WITH AN APOSTROPHE. Ahem. Making a plural with an apostrophe has become so common that I think I’ve developed a permanent twitch.
I’m going to give an example with the word that I see most often violated: attorney.
- attorneys = more than one attorney
- attorney’s = belonging to one attorney
- attorneys’ = belonging to more than one attorney
Got it? Good. Now you can twitch, too.
Leading Geeks 
I am agreeing because I dislike very much when plurals are given apostrophes. Too bad it's hard to teach this over again to adults. It is as if exposure to the internet just degrades their ability to write coherently!