I have an Alienware M18x r2 laptop, and am trying to hook up 3 external monitors to it in a non-linear fashion. I've discovered a product called Matrox TripleHead2Go which should (hopefully?) let me do exactly this, but I'm still trying to work out the logistics of using it.
My laptop has the following output plugs: VGA, HDMI, and dual-mode DisplayPort. TripleHead2Go has a VGA model, but the achievable resolution is not as high as for the DisplayPort model. (3x 1680x1050 versus 3x 1920x1080)