I am wondering how some of you might accomplish the following:

I have our entire office going through a proxy to access the internet.
Some of the workstations are setup to be full time access by the MAC
Address/IP address.

We have clients that come in with their computers and want to use our
Interent. How can this be accomplished without allowing the rest of the
office to have full access to the internet and how can I allow the client
full access to the Internet without giving out passwords?

Just wondering,