NoMachine's FreeNX is another solution to this that's been discussed on the list before, and there RPMs available in the extras repo. http://lists.centos.org/pipermail/centos/2005-August/050722.html
You get a more RDP-like connection (separate desktop than your console) if you like, and SSH encryption be default. The free edition server is available free for Linux and Solaris, with clients for Linux, Solarix, Windows and Mac OSX.
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- Kevan Benson
I'll have to check this out as well.
By the way, the Centos VNC server also provides a separate desktop (Windows UltraVNC server does not).
Michael