abc   Thu Sep 28, 2006 1:28 pm GMT
Does it stand for anything?
Jim   Thu Sep 28, 2006 11:22 pm GMT
I'd say that it's likely a variation on "psst".

abc   Fri Sep 29, 2006 12:02 am GMT
I also found this, but it's making no sense:
Jim   Fri Sep 29, 2006 12:30 am GMT
So it looks like a thing that a handful of teenagers are into do at the moment. They do this gesture and make that sound and it probably is funny or even cool to insiders but I'll bet it just looks absurd to outsiders. It'll most likely die out in a couple of years.
Jim   Mon Oct 02, 2006 5:02 am GMT
"... into doing at the moment."