Running two X servers?

I normally run Xorg with 1280x1024 resolution. I don’t know much about configuring it manually; I just use SaX2 to find what looks/works best. This resolution is ideal for my primary display and 95% of everything I do.

I also have a 37" LCD TV hooked up to the same system on the same video card (NVidia GeForce 7600 GS). I have them set up in Clone mode (though I’d be just as happy with the Xinerama mode; doesn’t really matter). The TV display only works properly using 1024x768.

As it stands now, if I want to watch a movie on my TV full screen, I have to change the resolution in SaX2 and restart X. It’s very annoying, especially when I have lots of X apps running.

My question is whether it’s possible to run two simultaneous login sessions as different users and with different X server settings. How difficult is this to configure, and where would I start? Or is there a better way to solve this problem?

Any help would be appreciated!