ZVNC is an experimental derivitave of two open source projects: VNC and 
ZeBeDee, a utility to set up encrypted, compressed tunneling between two 
hosts. It is possible to use ZeBeDee with VNC without using ZVNC, but 
doing so requires additional configuration of both client and server, and
inherently is less effecient and more prone to error than using VNC alone. 

ZVNC integrates encryption and compression into VNC, while remaining compatible
with both ordinary VNC and with configurations where VNC and ZeBeDee were used 
in combination.  Perhaps surprisingly, the compression component of the
combination is a significant improvement over VNC alone. 

Download the Binary distribution here, Windows only: 

               http://home.attbi.com/~davedyer/znc/zvnc.html