Internet acronyms -What do they mean and when to use them

Having been chatting on the net for a long time, I use internet acronyms in most of my day-day conversations over instant messengers (IMs). When you get used to them they're massive timesavers but before then it must seem like they're leaving out a lot of letters -producing gobbledy goop! Although some acronyms are phonetically based, many are are not and often confusing, so sparked by a number of people new to IMs constantly stopping me and asking what it meant (so not making it a timesaver at all while I either typed it out or found a dictionary of acronyms) I decided I would overview a list of acronyms that I use on a regular occasion as a reference point, I may add more later and I hope its of use to someone else out there (please note some of these are just ones that I've made up/use to aid development talk).

General

gtg

Got To Go

brb

Be Right Back (less than 5mins)

bbiab

Be Back In A Bit (5 - 15mins)

bbiaw

Be Back In A While (15mins +)

b

Back

wb

Welcome Back

ty

Thank You

yw

You're Welcome.

atm

At The Moment

ttyl

Talk To You Later

styl

Speak To You Later

cya

See You

cu

See You

afaik

As Far As I Know

afaiaa

As Far As I Am Aware

afaiac

As Far As I'm Concerned

afaics

As Far As I Can See

afaict

As Far As I Can Tell

b/c

Because

w/

With

w/o

WithOut

g/f

GirlFriend

b/f

BoyFriend

gl

Good Luck

omg

Oh My God

faq

Frequently Asked Question(s)

nm

Never Mind

n1

Nice One

n2s

Needless To Say

nn

Night Night

n00b

A inexperienced and / or ignorant or unskilled person (especially used in computer games)

nmp

Not My Problem

nmj

Not My Job

pwned

Beating / Defeating / Outclassing someone

lol

Laugh(ing) Out Loud

k

Ok

btw

By The Way

lmao

Laugh(ing) My Ass Off

wrt

With Regards To

Ones I don't tend to use but I frequently see

wtf

What The F***

wth

What The Hell

fo

F*** Off

fk

F*** Knows

fa

F*** All

sfa

Sweet F*** All

ffs

For F***'s Sake

po

P*** Off

Technical

w/s

Web Service

se

Search Engine

seo

Search Engine Optimisation

Smileys

:)

Smiley / Happy

:D

Mega Happy

:(

Sad

;)

Winking

:P

Sticking Toungue Out

:o

Surprised

:|

Disappointed

:S

Confused / Worried

:#

Don't Tell Anyone

:'(

Crying

>:(

Annoyed

:@

Angry

|-)

Sleepy / Tired / Yawning

Actions

When a phrase is contained in <> it generally refers to an action the user is doing

<g>

Grin

<bg>

Big Grin

<vbg>

Very Big Grin

<vbeg>

Very Big Evil Grin

When a is contained in >< it means the user is referring to himself
i.e. >Thinks its too late to be writing an article<

It may also be worth checking out: Google as there's many more complete dictionaries out there!