How do I set up Xfce to operate remotely?

[Todd and Margo Chester]

Hi All,

I have three CentOS 5.4 servers I need to remote
administer.  All three have Xfce 4.4.2 (no RPMs, so
I can not upgrade) on them.

How do set up Xfce such that I can remotely operate
it from both Linux and Windows clients?  Sort of like
Terminal Services, only the server is Linux/Xfce.

Many thanks,
-T