Program: Gbridge
License: Freeware
Description: Gbridge is an extension to Google's Gtalk network service. It automatically forms a VPN between user's multiple computers if logged in under same Gtalk user account. The VPN can also be extended to Gtalk friends based on invitation. (http://en.wikipedia.org/wiki/Gbridge)
Website: http://www.gbridge.com/
Other: none atm
Would be awesome to see this as a portable app, really awesome. Sorry I can't provide any "Other" information atm don't have access to registry later on I'll be sure to add more info aswell. Hopefully someone would've already done that anyways checked the forums no discussions about Gbridge so I'm good to go.
I am not sure, but this might not be possible. Since when you install Gbridge, you also have to install some drivers. It's probably not possible to make the drivers portable. But I think the just making a portable version of the Viewing client might be possible, which is more useful anyway; as you don't need a portable server, but a portable client for a stationary server.
Again, this is my very uneducated opinion.