Charles Schoenfeld gives us this freeware that serves as an Automator action for changing location-related settings and preferences. LocationSwitch v1.0 affects the settings of network location, sound volume, SMTP servers, automatic fetching of mail, enabling/disabling of individual e-mail accounts, and default printer selection.

The author of this app suggests that if you're routinely switching between two locations, better make two copies of this app - name each one to reflect your locations (e.g. SwitchHome and SwitchOffice). When starting up your computer from one location, click on your location's action to get started.

Customization is needed to have this software working. To apply personalized settings, LocationSwitch makes use of Applescript. Drag the icon for LocationSwitch onto the Automator icon and Automator will open, allowing you to customize it. Here's the detailed instructions from the download file:

In Steps 1 & 2:
Customize the alert and the network location to represent the relevant physical location.

In Step 3:
Customize your volume settings for the amount of ambient noise at the specified location.

In Step 4:
If you have more than two mail accounts set up, duplicate the line that changes the SMTP server as many times as necessary, editing the name of the account and the SMTP server for each.

In Steps 4 & 5 (yes, this also applies to Step 4):
Customize the names of your e-mail accounts (matching what you called them in Mail.app) and your SMTP servers.

In Steps 5 & 6 (yes, another instruction that applies to Step 5):
You may need to change some instances of the word "false" to "true" if you're trying to turn things on rather than off.

In Step 7:
Change "Home Queue" to the name of your default printer at the specified location (exactly matching the name of that printer in your Printer Setup Utility application).

Finally, delete any steps that you don't want to use. I recommend doing this last, so that the numbering of steps in the instructions above still makes sense. (Seasoned Applescripters will realize that I could have combined Steps 4–7 into a single step. This is why I didn't. Some people will not want to use every step, and separating them makes them easier to delete selectively.)

Download: [LocationSwitch]