Certain OS installers cough*osx*cough don't like the on-board displays on some machines. [Ziddan] posted a paperclip based work around for them on the eeeuser forums (originally posted by [mugan] on insanelymac). Apparently by shorting the pins, the video card will report that there is an unknown external display attached.
http://www.hackaday.com/2008/04/26/ghost-external-vga-display-hack/