I propose adding a feature to always replace "seperate" with "separate" in all question titles, questions, answers, edit summaries, and comments.
I'm asking just because I see it all over the place and, well, yes, it drives me a little nutty.
Perhaps /\bsep(e)rat(ion|e|ly|ed)\b/ig.replace('$1', 'a')
or something close would do. I forget if javascript uses $
for regex replacements.
Update
BAH HUMBUG!
Okay, I wasn't really serious. But it was fun to try. :)