There are lots of different types of VPNs based on how they are used. Some VPNs like those from Citrix GoToMyPC create a VPN connection so you can safely access your home computer from anywhere in the world. Other VPNs like those from Kovurt and OpenVPN focus on privacy and circumvention so you can access the Internet safely and privately. And there is a third type of VPN usage: creating a true private network so you can exchange files, chats, and messages with friends.

In this third type of VPn usage, a fantastic piece of software is Gbridge. Here is how Gbridge describes itself:

Gbridge is a free software that lets you remotely control PCs, sync folders, share files, and chat securely and easily. An extension of Google’s gtalk service, Gbridge automatically forms a collaborative, encrypted VPN (Virtual Private Network) that connects your computers and your friends’ computers directly and securely with patented technology. Gbridge has many unique features.

Not only does Gbridge let you privately chat with friends, it is also a fantastic computer backup solution, as well as a normal VNC. That means you can use it to troubleshoot other computers or access them in the same way GoToMyPC does it.

It is a great way to transfer very large files between friends or colleagues, and Gbridge use Dynamic DNS.

A couple caveats:
1) Gbridge only works on PCs. So Mac lovers are out of luck.

2) You must use a Google account to access it. Gbridge is not owned or related to Google, but it does use Google’s gtalk service so you must login with a Gmail or Google Apps account. You may worry that Gbridge or Google will then have access to your info… Gbridge “promises” everything is encrypted and they have no access to anything you transmit.

You can get more info at http://www.gbridge.com