The number given to your Steam account.
The 1st steam Account was 0:0:1, the second was 0:0:2 and so on.
The lower the STEAM Id the rarer the account is and the longer the person has been playing.
Leagues such as CAL,OGL,CPL and TWL require you to enter your Steam ID so they can verify its really you playing.
"Wow dude that guy who joined STEAM Id was 0:1:20031934 he must be a really bad n00b!"
A map in the Counter Strike Series in which players are only allowed to have a Knive and a Scout.
Most "SK" players learn how to do a trick called "sky strafing" which enables you to glide through the sky.
The second talent most "SK" players need is to beable to "noscope" which is shooting the enemy without croosshairs.
CS:S player1: "Wow he can noscope so well in scoutsknives!!"
CS:S player2: "Yah he probably painted a dot on his screen to know where the crosshair is that nerd!"