I have a development network where users can use one of three proxies to browse from different places. Its easy enough to get a plugin for browsers to let users switch but its hard to help users not browse out of the wrong one and get confused. I currently just use a basic squid proxy for each but I can change the proxy, or the user plugin.
What I am looking for is ideas where users are clear on where they are browsing from - this could be a banner injected into all pages (but must not affect the sites themselves that are shown, so a frame or something, or even just a coloured border around a page), a toolbar that shows the proxy being used or some other kind of alert.
Any ideas?
--Chris