the Most Commonly Misspelled Words.http://www.barnsdle.demon.co.uk/spell/error.html

 http://www.barnsdle.demon.co.uk/spell/error.html

A Study of Some of the Most Commonly Misspelled Words
I made a search of posts to Internet (Usenet) newsgroups using
Deja News < http://www.dejanews.com/ > coming up with a count of how many times a word was spelled with the conventional spelling and comparing this with how often it was spelled with an alternative form, or "misspelled." (This was inspired by a discussion in the newsgroup "alt.usage.english" in which a similar, but smaller, study of a few misspelled forms was done using a search engine.) Spellings other than the standard form were used more than 33% of the time for these words in posts to Usenet discussion groups: minuscule 68% of the time spelled otherwise
millennium 57
embarrassment 55 (embarrassing 35%)
occurrence 44 (occurring 37)
accommodate 40 (accommodation 39)
perseverance 36
supersede 35-50 (superseded 44)
noticeable 35
harass 34
inoculate 34