First, if you don't know what Captive Portal is...look here...http://www.personaltelco.net/index.cgi/CaptivePortal

Since Knoppix is a CD based distro, I think including a wireless gateway/authentication scheme such as that of captive portal as an option (by enabling) - this would be great for Wireless hot spots.

For instance, I want to set up an Access Point (AP) for friends/cowokers to surf the Internet using Wireless; however, I want their browsers to automatically be redirected to an authentication page. If their username/password exists on the system then their initial destination (ie. www.yahoo.com) would go through; otherwise they will get access denied.

This can be modified for commercial implementation at a hot-spot, small business, just nice and want to give free internet =).

I hope this is easy enough to implement. I know how to do this is Windows 2000 using Proxy Server or ISA but I am too new for Linux to begin...but if you guys have an idea, please share them. Where to start, step-by-step - good documentation.

Please do not say read iptables and read this or that....question is - what's the high-level thought process to make this work?

Thanks