nvidia dual head with one rotation in X

First, use nvidia-settings to generate xorg.conf with the following settings:

• Check "Enable Xinerama"
• Set every screen to "Separate X Screen"
• set relative position (left of, right of, etc.) in "X Screen" tab

Then edit /etc/X11/xorg.conf, add the following line in Monitor Section:

    Option         "Rotate" "left"

Tested on debian lenny(stable), glx-nvidia, XServer 1.4.2.