It's best use is when the conversation has become confusing or unclear and the user wants to kill the conversation or person(s) perpetuating the conversation because the user isn't sure what else to add to the conversation.
This term originated when Gamers-Forum user RaiDae simultaneously demonstrated and created the word in the Gamers-Forum IRC.
Rai: but i don't really notice the difference... except for one being bigger
Diligence109: led's have a better response time
Diligence109: less screen lag
Rai: ah. i see
Diligence109: that's pretty impoartnt for most genres of gaming
Diligence109: when those handful of miliseconds really do make a difference
Rai: weird though. there's a longer delay on guitar hero on the led than on the plasms
Rai: and the plasma is the bigger of the two (by a long shot)