On Dell Precision M4600 (Windows 7 x64) with Nvidia Quadro 2000M delivered in May 2012 I have been able to run two extra Samsung 191T LCD monitors (19") with the following configuration:
The left monitor of the pair is plugged into the VGA port in the back of the laptop using VGA connector cable that came with the monitor (191T comes with both VGA and DVI cables).
The right monitor of the pair is connected to a DVI cable, which is then connected to a DisplayPort adapter for use in display port on the rear of the right side of the laptop.
Be sure both monitors are powered off when making hookups. 191Ts have 1620x1050 resolution; the laptop screen has 1920x1080 resolution.
To get the two monitors running, turn them on, then go to Control Panel > Adjust Screen Resolution > Appearances and Personalization > Display > Screen Resolution. In this window click on Monitor 2 and at "Multiple Displays" select "Extend Desktop to this display" Click Apply, and Save Changes. Go through these same steps for the Monitor 3, and you have three screens running. Does fine for 3D CAD modeling (MicroStation v8i ss2). The software takes care of the differing screen sizes with no input from me.
You have to go back through these steps to disconnect each monitor. The connections will survive hibernation most of the time.