-When you write down things as "u" and "r" and so on.
-When you say lol, rofl, or roflmao instead of laughing. (Not guilty, but I have almost sometimes!)
-When you have mIRC or IceChat in the startup group (windows users)
-When you get in trouble with the law and try and use the /nick command to change identity.
Plz post sum more.