I've been using tinyspell (a spell checking software designed to work in every application) for a couple of days now, and I'v enjoyed every second of it. Frankly, I don't see why some of you are so adamant about keeping mIRC spell-checking free.
Adding missing words to the dictionary is only a matter of a couple of hours of chatting, and once spell checking is implemented it won't take long before people will start sharing their custom dictionaries to avoid having to add the missing words themselves, so that's one worry gone.
Another argument claims that people will just ignore the red squiggly underlines. As that might be true, people who will ignore it are probably the same people who will just turn off the spell checking feature all together. I mean, do you ignore chrome's spell checker? Probably not. If you care about spelling while chatting as much as you care about it while writing a comment on a forum, then I'm betting you won't ignore the red squiggly underlines. I certainly don't ignore tinyspell's tip boxes.
Sure, it won't stop people from mixing up "pic" and "pig", but that's just being petty... False positive/negatives exist in every software that has spell checking and it's just a matter of getting used to it and knowing how to spot the errors.
