Used primarily as a declaration of superiority in a verbal encounter. Similar to 90's "Suck it!" and "Gotcha" and declared with an "In your face!" attitude.
From the NBC hit-comedy 30 Rock:
Jenna: First, I was great in that "Arliss!" Second of all, if the president is so serious about the war on terror, why doesn't he hunt down and capture Barack Obama, before he strikes again? Its time for a change, America. That's why I'm voting for Osama in 2008!