Setting up OS X as a VPN server

If you have spent any time in the corporate world you have probably heard of VPN. Virtual Private Networks are a way to securely connect to one network, say your work's network resources, from another place (like your home broadband connection). OS X server has a VPN server baked right in that allows both OS X clients and Windows clients to connect securely, but how do you set it up?

Maclive.net has just posted a great article that explores setting up an OS X VPN server as well as connecting to that server from a Mac or a Windows box.