That's a pretty neat concept, but unfortunately that script hasn't been updated in two years and consequently does not work with the newer versions of vBulletin (which this forum uses). I looked for something comparable but couldn't find anything.
So red_fx2s suggestion is the best solution for now, hit the "new posts" button every so often and you get a similar effect.
2006 Ford Ranger Sport 4.0 2WD on 32x11.50R15s
-3" Doetsch Spindle Lift