Travel Technology - Laptops, Proxies, and Profiles

So I picked up a damn IT job while waiting to get back on a firetruck, and I find it ironic that I need to ask such a question, but here goes...
The company I am consulting for puts me with a client that uses a proxy server. I use my laptop, and my only internet apps are IE, Firefox 2, and Yahoo Messenger. Is there any profile manager, etc. that could change the proxy for all three on the fly, for example, no proxies while at home, same proxies for all three when at the client?

http://www.mobilenetswitch.com/

Enjoy.

Great software - I see that it will change the proxy settings for IE and Firefox - I can't determine, though, if it will do anything for Yahoo Messenger?

Great software - I see that it will change the proxy settings for IE and Firefox - I can't determine, though, if it will do anything for Yahoo Messenger?Yahoo Messenger will follow MSIE proxy settings, if you set it to the "No Proxies" mode ...