Mac OS X 10.4, one of its most awesome features is the integrated spell check, almost every where you can type you can spell check, I use it all day all night and love it very dearly. I found once that it had named "w00t" incorrectly spelled, however it did have two suggestions: "w00" and "00t." I certainly did not teach it those erm... "words." Anyway, it was interesting to me.