Acronym for "Laughing Loudly To Myself."
Used to express genuine interest, unlike "LOL".
Actually paying attention:
You: I just found out I have herpes...
Me: Holy crap man, I'm so sorry. Are you sure it's not an ingrown hair? Maybe
frostbite...Have you been sticking your dick in snow lately?
You: LLTM, Dane Cook is fucking kickass.
Not paying attention:
You: My wife died today, Tim. I'm contemplating suicide.
You: I'm serious here, Tim, I thought you would be more understanding.
Me: lol ok