People that use "ur" "asl" (specialy asl) "4" "ctc" in place of full words annoy the heck out of me.
"irregardless" is a minor annoyance. oh, can't forget "meh", it (meh) is like grunting, I just want to slap people that say "meh" upside the head with side of raw beef.
Incorrect spelling and grammer while annoying are not as bad as just being too plain lazy to type correctly.
Having something like ADD is no excuse for laziness like the above.
And yes I have laughed out loud when reading stuff @ the computer. Sometimes at inapropriate times like when a customer is telling me how they've lost 2 years worth of data because they didn't back up and I just read a particularly good punchline at a comic site. I've also had to dry off the screen because I took that sip of coffee when i shouldn't.