WTF does this mean?

Do you need help interpreting all those little collections of letters like "WTF?" These little guys are very popular in IM (instant messenger) and in email. Okay, most people who have been online for a few years or even a few months probably know that wtf stands for "what the fuck?" But what about all the others?

First off, you should know that they can be capitalized or lower case. When in capitals, it is just emphasizing. For example, lol means "laugh(ing) out loud." If capitalized, LOL means laugh(ing) out loud very hard. Get it? Good. Now on to the list.

In no particular order:
lol = laugh out loud
ttyl = talk to you later
omg = oh my god
omfg = oh my fucking god
jk = just kidding
wb = welcome back
rofl = rolling on floor laughing
lmao = laughing my ass off
lmfao = laughing my fucking ass off
gr8 = great
hago = have a good one
gfy = go fuck yourself
brb = be right back

This is far from a complete list. But I hope it helps.