The Google Toolbar, in addition to being an easy access to the Google search engine, has, among others, a spell checker. You click on spell check, the misspelled/unrecognized words are flagged, and you can right click to accept the suggested spelling or add it to the dictionary. As an example, the first word in this posting was “THe.” I also left out the “d” in “words.” It highlighted these words and suggested “The” for “THe” and “words” for “wors,” along with several other possibilities.
You owe it to yourself to check it out. The toolbar also has a great pop-up blocker and other handy tools.