Quote From pm133:
A serious question given all the posts about typos above. Are you talking about spelling errors or grammatical errors? Surely everyone uses a spell checker for the first?
That doesn't stop the wrong word correctly spelled sneaking through. Hence someone I know only spotted in the middle of printing that his thesis said 'pubic health' instead of 'public health' in one place.
Also worth bearing in mind that for very long documents Word gives up the ghost when it comes to underlining stuff. I've just worked on a report that was around 100K+ words where there were so many bits of science jargon and author names, Word gave up highlighting them, necessitating a manual click through spell check. Given how long it takes to do that, it's still possible to miss stuff unless you're uber focussed.