And about to do goodness knows what.

bak Back at keyboard

Having done goodness knows what.

bfn Bye for now

Tells others you're stepping away for an indeterminate amount of time.

Variations: b4n, bbl (be back later).

brb Be right back

Announces a brief absence, as if you're pausing to read a Shakespeare sonnet.

cu See you

The more formal version of cya (See ya).

ltns Long time, no see

A polite way of saying "I forgot you even existed," which could be abbreviated as ifuee.

ttfn Ta ta for now

What Zsa Zsa Gabor might say when exiting a chat room.

Variation: l8tr (later).

Flaming and Feuding
gal Get a life

The exact opposite of hand (have a nice day).

kiss Keep it simple, stupid

An impolite way of saying ot (off topic).

pu That stinks

tswc Tell someone who cares

Hooting and Hollering
gfete Grinning from ear to ear

Indicates mild amusement in which minimal dental work is displayed.

lmao Laughing my ankles off

The third word can also refer to another body part.

lol Laughing out loud

An appropriate response to a humorous statement. Alas, it doesn't necessarily mean lots of love.

rotfl Rolling on the floor laughing

Use when you couldn't possibly be more amused. Unless you're rotflmao, of course.

Opining and Informing
aamof As a matter of fact

Though in cyberspace, the fact could just as well be fiction.

afaik As far as I know

Use when you really don't know, but want to appear as if you do.

Variations: afaic (as far as I'm concerned), afaict (as far as I can tell).

btw By the way

A kissin' cousin to fyi (for your information) and fwiw (for what it's worth).

damhikt Don't ask me how I know this

For those obscure factoids your friends tease you for remembering.

eod End of discussion

Use EOD after the 163,456th chat-room message about the new "Star Wars" trailer.

hth Hope this (or that) helps

imho In my humble (or honest) opinion

Commonly used to preface unsolicited advice, such as "If I were you, I would dump your no-account girlfriend immediately."

Variations: imnsho (in my not so humble opinion), imco (in my considered opinion).

ianalb I am not a lawyer, but...

As in, "IANALB I play one on TV."

j/k Just kidding

Best used when combined with the :) emoticon. For more on the world of emoticons, see Everyday Emoticons.

ot Off topic

A polite way of saying kiss (keep it simple, stupid).

otoh On the other hand

Indicates you were once a member of the high school debate team.

Exotic Acronyms
aiamuAnd I'm a monkey's uncle

Simian slurs are popular everywhere, and cyberspace is no exception.

bbfbbmBody by Fisher, brains by Mattel

Put another way: You have the physique of a Tonka truck and the intellect of Barbie.

cmf Count my fingers

Similar to, though different from, rml (read my lips) or tmt (tally my toes).

dgt Don't go there

Best emphasized by raising your eyebrows, placing one hand on a hip and with the other hand, wagging your index finger warningly -- though, of course, your readers will have to imagine that part.

dqydj Don't quit your day job

Or as they say on The Sopranos, 'fagiddaboudit.'

tmi Too much information