Hey guys I am know for misspelling and typos and for the longest time I didn't think Firefox checked spelling on this site. After some research I've found that you can enable it easily.
One you have typed up your post and are ready to Submit it, click the Source button in the Editor. This will switch to HTML basically so you'll see some weird characters and stuff if you're not familiar w/ HTML code. Then just browse through all the stuff you typed and fix all your spelling mistakes.
Remember, don't mess w/ any of the code or else it will mess up your post. You can press Source again to see the newly fixed spelling errors.
Hope this helps some people like me!! LOL.
***Hits Source button to check spelling***
UPDATE: I had 3 spelling errors!! LOL