On a windows PC, you can run X applications from a remote X based machine.
On that windows PC, you will need: an X server (bit confusing, because you are more like a client) like Xming and a terminal program like putty with x forwarding enabled.

If it is resolution wise possible, you can also take over a desktop just using VNC. Somewhat easier to configure and you can also control windows remote.

Good luck experimenting

Have a look at this
http://www.youtube.com/watch?v=S-MlasLCf1A

An episode of the Wire is started on an Ubuntu desktop, from an n900, after which the video that is playing on the desktop machine is shown on the n900 screen.

^ Thanks!

2nd freakin' line to write more letters.

You can get Xming and Putty and you can do pretty much anything you want.

Exactly the opposite - You view Your N900 application on other machine (linux with X based - native, windows - using special "client", which is in fact X server, no need to get into details before You already check how it works ). Thats why it's called 'X forwarding over SSH' - You can achieve it without virtual desktop, in fact You're just forwarding one program, not whole desktop. Got some advantages and disadvantages over VNC (most common Open standard for virtual desktop) and RDP (Remote Desktop Protocol - semi-open w$ndoze standard, capable of faster user experience while doing basic operations on files etc, but unable to project advanced applications like directx/opengl related. RDP is also possible on linux using special packages)

Take this with a grain of salt, as it's purely theoretical knowledge, I've never used X forwarding over SSH myself.

Important note - OpenSSH package for Maemo lacks some improvements of security - basically, reaction to exploits presented in late 2009, compromising -cbc encryptions in some cases. Prior to that, -cbc was default choice, it was replaced with ,-ctr in correct order of preferences. Of course, if one is feeling paranoical, banning -cbc as whole is also an option, although keeping them as fallback seems sane, due to specific and non-trivial nature of exploiting them (so, in environment controlled by Yourself, You use -ctr, because Your both machines support it and it's higher on client preferences list, but You retain possibility of connecting to other servers, that don't support ctr).

IIRC, 'Ciphers' in /etc/ssh/ssh_config should look like that, for best security and compatibility at the same time:
/Estel

You say you haven't used X forwarding personally..?
I've tried it a dozen of times, and come to the conclusion of this:
Forwarding apps from a desktop, fine. Forwarding from N900? No...
There is no pointer, and the way Hildon works is very different from any desktop window manager. Most apps from the N900 become hopeless to use, because there is no integration.
From the desktop it is fine as long as the app can squeeze into the screen.

But, Addison, there is something to put in the clear: SSH is a lot more fun when you have a Unix desktop. (I say Unix because Mac can also be used.)

I use Remote Desktop Viewer on my Linux Desktop. I put it aside on one of the desktops and have it running Skype, so I can use my laptop´s keyboard to type messages on my phone´s Skype instantiation. You´ll need X11vnc installed and running on your n900.

Not strictly ssh but it get the job done.

Generally, everything is more fun when one have a GNU/Linux desktop Yet, SSH'ing and VNC'ing to w$ndoze machine can be also a lot of fun. Windows armed with some .bat scripts and TigerVNC can be neat as WOL machine. Not doing anything that Debian can't do, but if one is tied to windoze by some reasons...

/Estel

I can use RDP on N900 to access my PC at home. Is there RDP client on N9?