Gibraltar Linux is interesting in that it's designed to be a secure Linux networking solution. It's very similar to Knoppix in that it's a bootable CD distrobution, but it's designed to be a secure router as opposed to a bootable demo version of Linux. Because it runs off the CD, someone can't exactly root it and change around programs to turn it into a zombie. What you could do is route all incoming traffic through a Gibraltar box, turning it into a DMZ of sorts, sending only authorized requests (such as web traffic or your video streams) to another box inside the network.