ANONYMOUS I bring my PowerBook between home and the office every day, and used this frequently under Panther. At first, living without it in Tiger was an inconvenience.
Thankfully, I've found that all the functions for which I used it (switching network location, switching SMTP servers, toggling automatic checking of mail, switching default printers, changing sound volume) can be performed with Automator & Applescript in Tiger. I've got the same functionality back, in the form of one double-clickable Automator icon on my desktop, and it's free!
(Version 2.0)