I did a quick try last night and can see it would take a little effort.
The first thing is that a TUN/TAP driver is required and it doesn't appear to be already part of SME 6.01 (version I'm using). See
http://hamachi.cc/tuntapAlso, 'make install' claims to work, but as soon as I did a 'hamachi-init' (per the README instructions) I got a message that
libgcc_s.so.1 is missing.
I'm new to SME Server, but have worked with other Linux systems. If anybody has any helpful hints, I'll keep hacking at this.
Also, I am going to look at OpenVPN in the meantime.
Rich