I like the overall idea here. It reminds me of the Gibralter (router/VPN) "appliance on a CD" (which I had deployed at a set of customer sites for a few years). Unfortunately the free versions of Gibralter weren't well maintained (I don't know if they even still exist).
One application I'd love to explore would be to create an image similar to one of these Turnkey products which would be used as a router/VPN appliance. In my case I'd want to have a kit which took the base packages, patched in a peer list, a set of pre-shared keys, passwords/passhrases, and some trusted router access lists ... then built the ISOs with those coded into it.
Here's the usage scenario:
I work for a company which has a significant number of small and home offices. I'd love to have a generic PC deployed to each ... with our custom TurnkeyVPN discs sent to them. Put in the disc, boot the system and leave it running in a closet.
The pre-shared keys and other data automatically connect the user to the corporate VPN. sshd is running on the router/appliance with pre-shared keys in the ~root/.ssh/authorized_keys file to facilitate remoe troubleshooting, etc.
And there's one other very important feature I'd add to this. The Turnkey node should also function as a server for a LiveNet rescue image! In other words it should be possible for anyone on its LAN to boot over PXE into a live image ... with its own ssh and other remote troubleshooting facilities started! Thus the home office user could, when is or her production desktop or laptop fails, boot over the local network and see a screen informing them that messages have been dispatched to the corporate help desk and someone will be logging in to assess the situation.
This should, of course, support remote re-imaging. That would not be directly part of the TurnkeyVPN/Rescue image. However, the TurnkeyVPN would provide the features necessary to support it. (In my case the recommended implementation of this other feature would be to trickle a full image of the user's desktop/laptop OS to the hard drive on the appliance node ... and to make it into a Kickstart/Partimage server as well as the VPN node. The data is trickled over slowly and updated during low utilization times while the user's desktops are functioning. So when they have a failure everything is already stage out there for a re-image. Naturally we'd sometimes have to send a new hard drive and rely on the end user to physically get it installed on the target. Also sometimes we might have to have them replace the hard drive on the TurnkeyVPN node as well.
It's also possible that we'd want to create three different Turnkey images from the foregoing requirements: TurnkeyVPN, TurnkeyRescueServer, and TurnkeyVPN+Rescue.
Anyway that's my idea. I'd love to see a HOWTO guide describing how these Turnkey images are created (the parts that they all have in common, of course).
(I've done the PXE LiveNet rescue images on a few occasions already, using KNOPPIX and Ubuntu has the base for variation iterations of this. So I am quite familiar with that process).