We've long been fans of this Facebook group, started by the delightful Sharon Eliza Nichols. Now, there's a book that collects all the hilarity of the bad grammar on signs, notes, and even baby bibs.
It's called--of course--I Judge You When You Use Poor Grammar. Do check it out, and report back to us with your favorite error. We really like the one that says NO ACOHOL BEYOND THIS POINT. To us, it sounds like one drink too many, already.