I change locations (use the Apple Menu -> Location menu item) at minimum twice every workday. I wanted to add shortcuts to make it easier/faster, but after adding the name of my location in the Keyboard & Mouse Preferences panel, it still didn't work. The shortcut shows in the menu item, but it only works after you have hovered over the "Location" submenu, and let it display the menu (and you have to do this every time an app is launched).
So I thought, why not have a keystroke do the job via Butler (or another similar utility)?
Note: Control-F2 (by default) selects the Apple Menu and it will prevent you from creating a keystroke with that definition. Before you proceed, you have to disable the 'Move focus to the menu bar' feature in the Keyboard & Mouse System Preferences panel. Look on the Keyboard Shortcuts tab, in the Keyboard Navigation section. Just uncheck the box next to this feature.
The three locations I use the most are in this order (at the top of the sub-menu):
Control-F2, Down Arrow, L, Right Arrow, Return
This changes the location to •Home. To switch to •Work | DTS Office, I did:
Control-F2, Down Arrow, L, Right Arrow, Down Arrow, Return
The keyboard shortcut/keystroke you assign it is also important. You want to avoid using Command, as it will hang up the process and prevent it from executing if you hold down the Command key too long (it hangs right after Control-F2). So to avoid that hassle, I assigned Control-Option-F1, Control-Option-F2, and Control-Option-F3 to my three most-used locations.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20060111163633659