I proudly parade around with the term "Grammar Nazi."
Chatspeak (any form) makes my fingers twitch, a bit of fingernail chewing, and a very "must-fix-now" feeling creep into my head. I'm diagnosed with Obsessive Compulsive Disorder and that's where my Grammar obsession comes from.
I think it's disrespectful to the English language and succeeds in making you look like an ignorant, uneducated, lazy person. Even in chat rooms. I like vowels, too, you little text-talkers. "I" is always capitalized--show some self respect, please. "R" is a letter, not a word. "U" is a letter, not a word. Punctuation and capitalization DO EXIST. They are very real! Get my point? However, I do know things like "lol", "rofl", "brb", and "gtg". They don't bother me too much.
Uhhh. And spelling errors don't make me too upset, but they're up there on my "Things I HATE" list. Spell-check is on the Google toolbar, on Firefox, and it's VERY EASY to type up ":insert your browser's name: spell-check".
Overuse of smilies is a pet peeve, but I don't get triggered by it. :l
:edit:
I forgot about random PMs.
If it's not just "hi", I'm okay with it. If it can be made into some form of conversation and they type correctly, I'll talk to them.