What is the story with CLEAR?

So I signed up for the new airport program called "CLEAR" and today at the SFO Northwest Airlines terminal I had my first experience... But now I just want to know what it is all about! Is this just an elaborate way to cut in line at the airport security line? I still had to go through the regular security procedures, like any other traveller... What is the story? Is this a half-implemented system?

Gleason

Gleason
Originally uploaded by Ted Shelton

"...it is the dogma of the few and not the faith of the multitude."
-James Connolly 1907

Starry Plough

Starry Plough
Originally uploaded by Ted Shelton

wasting away at the starry plough in Berkeley instead of being at the creative commons party..