I

IAC -- In any case
IAD8 -- It's a date
IC -- I See
ICQ -- I seek you
ICQ -- A chat program
IDK -- I don't know
IGotUBabe-- I've got you babe
IIRC -- If I recall correctly
ILU -- I love you
ILU2 -- I love you too
ILUA -- I love you alot
ILuvU Alwz&4evr -- I love you always and forever
IMO -- In my opinion
IMHO -- In my honest (or humble) opinion
IMBLuv -- It must be love
IMI -- I mean it
IMO -- In my opinion
IMTNG -- I am in a meeting
IM 4 U -- I am for you
Im :) 2hv Mt U -- I'm happy to have met you
IOU -- I owe you
IOW -- In other words
IRL -- In real life
Its F8 -- It's fate
IUSS -- If you say so
IYD -- In your dreams
IYKWIM - If you know what I mean