... LOL ... ROTF ... FWIW...
What Those Strange Acronyms Mean


2U2 - To You Too
404 - I have no clue (Bad URL/Page Request)
A/L - Age/Location
A/S/C - Age/Sex/Check
A/S/S/C - Age/Sex/State/Check
AAMOF - As A Matter Of Fact
AFAIK - As Far As I Know
AFAIC - As Far As I'm Concerned
AFAICT - As Far As I Can Tell
AFK - Away From Keyboard
AMF - Adios My Friend
AMF - Adios Mo Fo
ASAP - As Soon As Possible
ASL - Age,Sex,Location
BAG - Big @ss Grin
BAK - Back At Keyboard
BBL - Be Back Later
BF - BoyFriend
BFD - Big Fricken Deal
BITMT - But In The Meantime
BOT - Back On Topic
BRB - Be Right Back
BSEG - BIG Sh*t Eat'n Grin
BTW - By the way
C4N - Ciao For Now
CRS - Can't Remember "Stuff"
CU - See You
CUL8R - See You Later
CWOT - Complete Waste Of Time
CYA - See Ya
DIY - Do It Yourself
DYG - Damn You're Good
EOD - End Of Discussion
EZ - Easy
F2F - Face To Face
FAQ - Frequently Asked Questions
FBOW - For Better Or Worse
FOAF - Friend Of A Friend
FOCL - Falling Off Chair Laughing
FUBAR - Fu*ked Up Beyond All Recognition
FWIW - For What It's Worth
FYA - For Your Amusement
FYI - For Your Information
/ga - Go Ahead
GAL - Get A Life
GBTW - Get Back To Work
GF - Girlfriend
GFC - Going For Coffee
GFETE - Grinning From Ear To Ear
GFY - Go Fu*k Yourself
GMTA - Great minds think alike
GR&D - Grinning, Running & Ducking
GTG - Got To Go
GTGTTBR - Got To Go To The Bathroom
GTRM - Going To Read Mail
GU - Geographically Undesirable
H8 - Hate
HAND - Have A Nice Day
HHOK - Ha Ha Only Kidding
HTH - Hope This Helps
IAC - In Any Case
IAE - In Any Event
IANAL - I am not a lawyer
IC - I See
IDGI - I Don't Get It
IMCO - In My Considered Opinion
IMHO - In my humble opinion
IMNHO - In my NEVER humble opinion
IMNSHO - in My Not So Humble Opinion
IMO - In My Opinion
IMPE - In My Personal Experience
IMVHO - In My Very Humble Opinion
IOW - In Other Words
IRL - In Real Life
ISP - Internet Service Provider
IYKWIM - If You Know What I Mean
JIC - Just In Case
J/K - Just kidding
KISS - Keep It Simple Stupid
L8R - Later
LBB - Little Black Box
LOL - Laughing Out Loud
LMAO - Laughing My Arse Off
LMFAO - Laughing My F*cking Arse Off
LTNS - Long Time No See
MorF - Male or Female
MTCW - My Two Cents Worth
NBD - No Big Deal
N/M/ - No Message (Used in subject line. No need to open. Subject line is the reply)
NRN - No Reply Necessary
NTK - Need To Know
OIC - Oh I See
OLL - Online Love
ONNA - Oh No, Not Again!
OTOH - On The Other Hand
OTTOMH - Off the top of my head
OTF - On The Floor
OYH - Over Your Head
PIP - Pee'n In Pants
PITA - Pain In The @ss
PLS - Please
PMP - Pee'n My Pants
PMSL - Pissing Myself Laughing
PSL - Pissin Self Laughing
PSTFU - Please...Shut The Fluck Up
PU - That Stinks!
REHI - Hello Again (re-Hi!)
RL - Real Life
ROFL - Rolling On Floor Laughing
ROTF - Rolling On The Floor
ROTFL - Rolling On The Floor Laughing
RSN - Real Soon Now
RTDox - Read The Documentation
RTFM - Read The Frickin' Manual
RUOK - Are You OK?
RW - Real World
SNAFU - Situation Normal All Fouled Up
SO - Significant Other
SOL - Smiling Out Loud (or Sh*t Out of Luck)
TANSTAAFL - There Ain't No Such Thing As A Free Lunch
TAFN - That's All For Now
TEOTWAWKI - The End Of The World As We Know It
TMI - To Much Information
TTFN - Ta Tah For Now
TY - Thank You
WEG - Wicked Evil Grin
WTF - What The F*ck
YW - Your Welcome

Some Additions

LBB - Little Black Box
DYG - Damn You're Good
(this is just from me 2u<==<.... muahaaa......)