I'm an English teacher. I have a bulletin board in my classroom titled "Grammar Spy". On this board, the kids can bring in any printed grammatical errors they find and they will get credit for posting the clipping. They actually try to have fun with it and are eager to be more careful readers.
I, too, have a hard time dealing with such errors. I am told that I am quite annoying because I often correct people when they speak and when they write. I teach 8th grade and correcting grammar, spelling and usage seem to be one of the largest parts of my job. Some of the students listen to me and pay attention. Some continue to make the same mistakes over and over. I have little patience for mistakes made by adults who should know better. I know it's not very nice, but sometimes, I just can't help myself.
There have been times when I have had to restrain myself from correcting someone...but I think...doesn't everyone want to know the proper form and usage? Doesn't everyone want to know how to say or write things correctly?