OK, I still don't understand how they work, but I see that you guys are serious about these WootOffs and other Woot deals, so here's what you need.
Go to http://www.deliciousmorsel.com/app/wooton
to see WootOn!
This is the FREE Woot.com Tracker App For Your iPhone.
It will enable you to track Woot.com, Shirt.Woot, Wine.Woot and Sellout.Woot with ease from your iPhone, and if you set it up for auto-refresh, it will remind you when a product sells out or changes during a WootOff!
There's also a beta version for the Palm Pre - http://www.deliciousmorsel.com/app/wootonwebos