Emacs Tip #3 -- Flyspell Auto Correct Word
flyspell-auto-correct-word, bound to C-. (control-period) in Emacs 22,
replaces the last misspelled word with the closest match in the
dictionary. Press it again and it picks the next closest match.
Repeat until you find what you are looking for.
If you are using an older verison of emacs that doesn't have this
binding predefined, simply add this to you
(global-set-key [(control .)] 'flyspell-auto-correct-word)
This is usually even faster than M-$, which shows all of the options