If the acronym you want isn't listed here, try the Jargon Buster

AAMOF		As a matter of fact
AFAICT		As far as I can tell
AFAIK		As far as I know
AFK		Away from keyboard
AIUI		As I understand it
ASAP		As soon as possible
B4		Before
BAK		Back at keyboard
BBL		Be back later
BBIAB		Beback in a bit
BCNU		By seeing you
BRB		Be right back
BSF		But seriously folks
BTDT		Been there, done that
BTW		By the way
BWQ		Buzz word quotient
CUL		See you later
CYOTFS		Catch you on the flip-side
DYJHIW		Don't you just hate it when ...
ETLA		Extended three-letter acronym
EOF		End of file
F2F		Face to face
FAQ		Frequently asked question
FFS		For fuck's sake
FIIK		Fucked if I know
FOC		Free of charge
FUBAR		Fucked up beyond all recognition
FWIW		For what it's worth
FYE		For your entertainment
FYI		For your information
		Grins
GIGO		Garbage in garbage out
HTH		Hope that helps
IAE		In any event
IIRC		If I recall correctly
IME		In my experience
IMHO		In my humble opinion
IMNSHO		In my not so humble opinion
IMO		In my opinion
IOW		In other words
IRL		In real life.
ISP		Internet service provider
ISTM		It seems to me
ISTR		I seem to recall
ITRO		In the region of ...
IYSWIM		If you see what I mean
JAM		Just a minute
KISS		Keep it simple, Stupid
L8R		Later
LAITW		Look at it this way
LOL		Laughs out loud
LTNS		Long time no see.
M8		Mate
MYOB		Mind your own buisness
NP		No problem
NRN		No reply necessary
OEM		Original equipment manufacturer
OIC		Oh, I see.
OTOH		On the other hand
OTT		Over the top
PD		Public domain
QT		Cutie
ROTFL		Rolls on the floor laughing
RSN		Real soon now
RTFAQ		Read the FAQ
RTFM		Read the fucking manual [or message]
RTM		Read the manual [or message]
SITD		Still in the dark
SNAFU		Situation normal, all fucked up
SNR		Signal-to-noise ratio
SSDD		Same shit, different day
STFU		Shut The Fuck Up!
TAM		Tenner a month (account fee).
TBH		To Be Honest
TIA		Thanks in advance
TLA		Three-letter acronym
TMTOWTDI		There's more than one way to do it
TTFN		Ta ta for now
TTYL		Talk to you later
WB		Welcome back.
WTF		What/Why the fuck
WYSIWYG		What you see is what you get
YMMV		Your mileage may vary