Say WHAT?

I've been chatting to people on the internet lately, and I need to know the lingo. I think I've figured out a lot of it, but please correct me if I'm wrong.

IMHO (in my humble opinion)

LOL (laughing out loud)

ROFL (rolling on floor laughing)

ROFLMAO (rolling on floor laughing my a__ off)

TMI ?

I don't have a clue what TMI means. Can anybody help me? And what other acronyms can I expect to encounter?

Thanks, bloggerbuddies! TTYL (talk to you later)!