Here are some common and not so common abbreviations you may see on the boards and in chat rooms on the internet:
BBL = Be Back Later
BF= Boyfriend
BIL= Brother In Law
BRB= Be Right Back
BTDT= Been There Done That
CU= See you
DH= Dear Husband (or Darn Husband)
DS= Dear Son
DD= Dear Daughter
FIL= Father In Law
FYI= For Your Information
GF= Girlfriend
IC= I See
IMHO= In My Humble Opinion
IOW= In Other Words
JK= Just Kidding
LOL= Laughing Out Loud
LTNS= Long Time No See
MIL= Mother In Law
PM= Private Message
ROFL= Rolling On Floor Laughing
SIL= Sister In Law
SO= Significant Other
TTFN= Ta Ta For Now
TWG= TightWad Gazette
TY= Thank You
WWW= World Wide Web
YW= Your Welcome
Hope this helps some of you who are new to the WWW!