Here's an interesting article from today's Irish Times - Typo vigilantes go on spelling spree. Two Americans, Jeff Deck and Benjamin Herson, have crossed America correcting spelling and grammar errors on signs as they went along. The even got arrested and fined! The fruits of their efforts are published in a new book - The Great Typo Hunt (this link is to the Amazon page where the "Look Inside" feature allows you to see some more examples).
I am one of those people who has a thing about typing errors. All modern word processing software has in-built spell checking. I am typing this post in a Google Chrome browser, which shows up errors as I go along. There is really no excuse for spelling errors - every email I send is checked for spelling before it is sent. It is rare that one of my emails does not have a typing error - thanks goodness for spell checking. I don't want people to think I can't spell. Checking spelling is quick and easy to do - why doesn't everybody do this?
If I see spelling errors in a document, I am certainly already on my guard - if there are typos, what other careless errors are there in the document? As part of my job, I read a lot of student essays, projects, and dissertations - and it is a bad start for the student if I detect typos on the first page (this happens a lot). Even my own College is not immune - we were exposed in June 2008 by the Irish Independent for having "its" instead of "it's" on a huge sign. We made the news two days running over this - culminating in a tongue in cheek article by John Walshe "Found: Good home for stray apostrophe"!
I have read over this post several times to ensure that there are no typos! (I hope I got them all).