I get annoyed when pop culture catchphrases are overused. I'm guilty of using the term awesome too much.
I was annoyed when the phrase, "NOT!" was popular when I was in high school, and "Yeah, right!" Both from Wayne's World I think. And my older brother drove me up the wall last year because he apparently became fond of the term, "Meh." He used it constantly. I'd say something like, "That movie was pretty good," and he'd say, "Meh." I felt like throwing a wet sock at him.
But yes, saying lull or lol in real life is kind of strange. I don't care when people use it online unless it's overused. There are not very many ways to get across that you liked someone's joke. Lol is just one of those ways.
And I think we should bring back, "Don't harsh on my mellow."