Some people are bad spellers or at least consistently have trouble with certain words. Others can spell but are poor typists and constantly mistype words. Some, I suppose, fall into both categories. If any of this describes you, don't despair: Bruce Connor has a solution for you.
Over at Endless Parentheses he presents a bit of Elisp that will look up the correct spelling with
aspell or whatever you're using) and make an abbreviation for your incorrect spelling so that it will be automatically corrected in the future. It's probably not for everyone but if you consistently make spelling errors—for whatever reason—it may be helpful.
Endless Parentheses is a fairly new blog that concentrates on short, mostly weekly, Emacs-oriented posts. As of this writing there are only eight short posts so you might want to read them all. It won't take much time and you'll probably learn something.