I have a handful of windows-based machines that i'm the primary support from...things from parents boxes to colocated servers. One of the most important features i make use of is mapping a given share from one of those boxes to a drive letter on my primary workstation. To date, i accomplish this using Hamachi's VPN software.
Hamachi's dead simple to setup and (for the most part) administer in that it doesn't demand that I master the intricacies of windows networking. The trade off is that it's very slow (for file transfer via mapped network shares).
I choose Hamachi after a brief attempt to deal with Windows' native 'Routing & Remote Access' server - the configuration of which proved to be too far over my head to be worth the effort.
But that was several years ago. I wonder if the emergence of Powershell as a scripting admin tool and/or windows server 08 has changed the landscape enough to revisit other forms of VPNing.