I spent some time this weekend proofreading Catherine Asaro's Aurora in Four Voices which is this year's ISFiC Press book for Windycon. It's amazing how spellcheckers have changed proofreading since my old fanzine days. Now, you're not looking for misspellings -- except for proper names -- you're looking for wrong words, missing words, minor punctuation and typography errors, and foolish consistencies.
Fortunately, I'm good at that too, not just at catching misspelled words. :)