Ask HN: Roll your own LogMeIn?

With the 7-day transition period for LogMeIn rapidly coming to a close I still haven't found a decent replacement for it (TeamViewer not working because of the commercial licensing aspect, I connect to various client work computers frequently).

Can we roll our own however? It seems like a lot of the components are available, they just have to be carefully constructed. Given the following list of components, how do we glue them together to get a LogMeIn-like experience (unattended remoting, NAT traversal, etc.)?

Obviously VNC is the first component that pops into my head. Second, I have a VPS that I use for hosting my sites and services; can it be used to centrally track where all my remote clients are? Third, what component would be needed to negotiate the NAT traversal, especially when computers are behind corporate firewalls (LogMeIn's killer feature IMHO?)?

Thoughts can also be appended here: https://gist.github.com/jlyman/8606354