Man, after setting up my new laptop I didn't realize that simple file sharing was turned on by default if your machine is not part of a domain.  To be honest, I don't think I've ever even used or seen simple file sharing.  I was trying to adjust the security on a folder and all I saw was the simple sharing user interface and I was wondering what the heck was going on.

From the KB article:

If simple file sharing is enabled, you see the simple file sharing user interface appears instead of the Security and Sharing tabs. By default, this new user interface is implemented in Windows XP Home Edition and in Microsoft Windows XP Professional if you are working in a workgroup. If you turn off simple file sharing, the classic Security and Sharing tabs appear, and you can specify which users and groups have access to shared folders on your computer.

Made the change as described in the KB article and back to normal - Woohoo!

Giddy Up!