rooSwitch is Nifty

Via [Daring Fireball](http://daringfireball.net/): "Nifty $15 utility by Brian Cooke; [RooSwitch](http://roobasoft.com/rooSwitch/) lets you switch between different “profiles” for application data. So, for example, you could create “Work” and “Home” profiles for an app like NetNewsWire — switching between RooSwitch profiles would allow you to switch between two entirely different sets of feed subscriptions."

rooSwitch has Applescript support, and of course Automator, with an included "Switch Profile" action. I've seen utilities like this for specific apps before, but a system-wide one is a great idea. The UI is simple and slick, too.