Seriously. Everyone makes spelling mistakes. Once you have Firefox, it will underline anything that isn't spelled right. You right click on the underlined word and select the word you were looking for on the drop down list. You can even just "guess-type" it and if you're lucky, you will find the right spelling of the word.
You can even install more dictionaries and all kinds of gadgets (weather alert,video downloader, blogging tools, and million other little tinker toys you wish)

http://www.mozilla.com/en-US/firefox/

addons:
https://addons.mozilla.org/en-US/firefox/?application=firefox

Yo dogggggggg waht's godo wiht it ?

tanks

lol...it also underlines words that ARE spelled correctly, which is more annoying that the typos...

*Another option... take a third grade grammar course.

Then comes in your own knowledge of spelling to realize it.

....I hate firefox. Never had anything but trouble with it. Of course that may just be me. Think I'll just stick with IE and my third grade grammer course.

switched to firefox at the peak of that IE exposure scare, been using it ever since. love the spellcheck since i type horribly with typos.