I just got in another monitor and decided to do a dual monitor setup on my computer. I configued Xorg so that it doesn't use xinerama so that I get two seperate displays (I can't keep my monitor next to the other, its above it so it looks kinda strange with it on). But theres problem, as I am running Gnome (2.6) I can't have two different panels or applets running at the same time or it crashes; an example: clock-applet or weather-applet. So is it possible to run two different 'gnome-session''s or run two different WM's at the same time?

Maybe you should look into fixing the problem of multiple applets crashing first. If is possible to run multiple window managers but I am not sure how you would run multiple instances of the same window manager. If you have KDE you can type startkde to start that within gnome. You can start other WMs with their commands also.