Windows XP System Restore got me up and running tonight. Thank Bill it was there.
I think it all started this morning when I loaned my laptop to Reed. (Gotta blame somebody.) Things literally just stopped working all over the place. Networking stopped working (both my broadband wireless card and my regular WiFi card). Then I couldn't open up any menu items. I mean things just went in the toilet really quickly.
I booted into Safe Mode with Networking (so my domain ID would work). Then I selected Accessories -> System Tools -> System Restore. It rebooted, restored, and rebooted again. Next thing I know, everything's beautiful.
If you're running Windows, you should be familiar with System Restore. If you're not, you might want to get a copy of my book .