Remote Graphical Login for Local User

[kingofqueens]

I have three machines running ubuntu:
My Server which runs Edgy
My Laptop which runs Gutsy
My Desktop which runs Gutsy

My server is the only computer which I am able to access from the Internet. So I can do ssh from my Laptop @ college to my server @ home. I can then ssh to my desktop. Knowing this, is there any command I can use to make my desktop login so that someone who is at it can use it without knowing the password? Think of it like how you normally login using your username and password only doing that from a distance.
I really hope that made sense.
Many thanks,
Thomas

[Banthaman]

you might want to look into freeNX - http://nomachine.com/

[daflame]

you might want to look into freeNX - http://nomachine.com/

That is NOT FreeNX. Please get the name correct. NoMachine has spent quite an effort to let people know they are not the same. The one on NoMachine's site is NX Free Edition. It is a commercial solution, even though it is offered for free, the code is still not open source and the server is limited to two connections and two users, and you have to pay to get more. FreeNX, unlike NX Free Edition is unlimited except by the physical hardware's capabilities (enough RAM and CPU power). If you want FreeNX for Edgy, I would recommend Seveas' repository. As for a recent version for Gutsy you can check out the forum I setup. It has repos for recent packages:
http://ubuntuforums.org/showthread.php?t=620057&highlight=freenx