Networking active X window screen (or just certain apps)

[OdinsDream]

So, I've learned a little about the networking possibilities with an X server/client setup. I've discovered how to start applications on my gentoo machine, but have them displayed on a remote system where I'm running ssh.

However, how can I do this with currently-active windows on the gentoo system?

Best example: Gaim. I leave gaim running all the time. I'd like to ssh to my box, and then display the Gaim client (as it's already running) on the remote server. I don't want to start another gaim session, or close the current session. I also want to be able to disconnect and Leave Gaim Running.

I used to accomplish this in windows with VNC. The Windows VNC server exported the Current Display. However, the Linux version starts up a whole new X server. While I can see how this would be useful, it's not what I'm looking for in this situation.

K Desktop Sharing has been mentioned before, but I'd like to move away from KDE, since fluxbox is what I use on most of my systems now.

[OdinsDream]

I guess more precisely, I'm looking for an implementation of VNC that works the same as the Windows version, which doesn't seem all that complicated...