I didn't think I used a spell checker, but Konqueror has check-as-you-type enabled by default. I don't care enough to switch it off. OTOH I find I can't use the check-as-you-type in Word because the squiggly lines are so distracting.

I ticked "I don't care if I spell correctly or not" because I think that I type and spell sufficiently well that nobody will think I'm a blithering idiot, at least, not due to my spelling.