Tried VNC today.

I had planned to test this for some time but only got around to it today.
In summary, everything went very well and this is so easy to set up.
This is a useful summary which I used to set things up in Ubuntu and Foresight. However, it contains a lot more than you really need.
Essentially, you just enable Remote Desktop in System>Preferences>Remote Desktop. Now you must install a program to enable you to see the remote screen.
In Ubuntu, a choice of four (vnc-java, tightvnc-java, xtightvncviewer, xvnc4server) is given and I installed xvnc4Server.
I found out what I needed in Foresight by running
conary rq --path=/usr/bin/vncviewer
which gave me three programs. I installed the vnc program.
However, although it seems to be recommended to use the host name to connect to the remote computer, but this simply didn't work for me.
What did work was this

vncviewer 192.168.1.12:0

which includes the IP of the remote computer and the screen number.
Linux-to-Linux asks for a password of the remote computer and that computer than is given the choice of accepting or refusing to allow access.

Kurumin uses a GUI (Krdc) for these connections and provides a choice of either vnc (to a Linux box) or rdp (to a Windows machine).
Strangely, it worked fine when I connected to Margaret's computer (Windows XP) but doesn't work at all for connection to a Linux box. when I try in a terminal (I installed xvncviewer here too), a window labelled with the correct remote host-name opens but nothing appears in it. It's just black.
Strange.

rdesktop works also on both Ubuntu and Foresight and is already installed on both.
In contrast to the Linux-to-Linux connection, connecting Linux to Windows opens a login screen on the client, but no accept/refuse is presented on the Server. Indeed, the server goes back to the login screen and stays there when the client is working on Windows remotely.