A

• AFAIK - As Far As I Know
• AFK - Away From Keyboard
• AOLer - America OnLine Member (note that AOL is international, despite the name, and there are many European AOLers)
• A/S/L - Age/Sex/Location

B

• BAK - Back At Keyboard
• BBIAF - Be Back In A Flash
• BBL - Be Back Later
• BD - Big Deal
• BFD - Big F***ing Deal
• BFN - Bye For Now
• BRB - Be Right Back
• BTW - By The Way

C

• CUL8R - See You Later
• CYA - See Ya

F

• FB - Furrowed Brow
• FWIW - For What It's Worth

G

• GDM8 - G'day Mate
• GMTA - Great Minds Think Alike
• GRD - Grinning, Running, Ducking
• GR8 - Great

H

• HTH - Hope This Helps

I

• IAE - In Any Event
• IANAL - I Am Not A Lawyer
• IM - Instant Message
• IMHO - In My Humble Opinion
• IMNSHO - In My Not So Humble Opinion
• IOW - In Other Words
• IYSWIM - If You See What I Mean

J

• J/K - Just Kidding

L

• LOL - Laughing Out Loud
• LTNS - Long Time No See

M

• M4M - Men seeking Men

N

• NFW - No F***ing Way
• NP - No Problem
• NRN - No Reply Necessary
• NW - No Way

O

• OIC - Oh, I See
• OTOH - On The Other Hand

P

• PBT - Pay Back Time

R

• ROTFL/ROFL - Rolling On The Floor Laughing
• RTFM - Read The Friggin' Manual
• RTM - Read The Manual

S

• SOL - Sooner Or Later

T

• TOS - Terms Of Service
• TTFN - Ta-Ta For Now
• TTYL - Talk To You Soon

W

• WB - Welcome Back
• WTG - Way To Go

Y

• YL/YM - Young Lady/Young Man
• YMMV - Your Mileage May Vary

Further Reading

• The Internet
• Email
• How to Fight Spam
• Usenet
• Internet Chat
• Internet Telephony
• Online Gaming
• The World Wide Web
• Web Authoring
• Netiquette
• Emoticons and Internet Smileys
• Internet Zones