I have been looking at running multi monitors off a laptop. In addition to the Matrox, USB, and highly expensive Digital tigers sidecar or Vtech box there is also MAY be this for running a X1 quad such as NVS440/20 or ATI firemV 2400 (note: max power for boxes of 36 watts is same as one 2d quad head graphic card and may not even run graphic cards):
http://www.amazon.com/Express-2PCIE...TF8&coliid=I14PJV373X0A2H&colid=2ECQDSUVX7TD2
Add four external I/O expansion card slots to a desktop or laptop computer system. StarTech.com's innovative PCI/PCI Express Expansion Chassis provides a quick and simple solution to I/O expandability on almost any PCI Express (PCIe) enabled system. Adding external PCI and PCIe slots to a server/workstation or laptop, this cost-effective and time-saving method of simply adding additional PCI/PCIe cards to a server/workstation or providing a platform to be able to swap PCI/PCIe add-in cards between a mobile and desktop setup is the optimal method of maximizing the I/O capabilities of new or existing systems.
The external expansion chassis adds two full length (38cm) PCI slots (32-bit/33MHz) as well as two PCIe x1 (single lane) slots to the host computer system, through a single PCI Express connection. Providing total bandwidth of up to 250MBps from the x1 PCIe host controller card, which allows the host computer to function as though the cards in the expansion chassis were connected directly to the motherboard.
For mobile applications, the Expansion Chassis can be connected to an ExpressCard enabled laptop using StarTech.com's ExpressCard connection cable (EC2PCI), which adds the same functionality offered by the Expansion Chassis to a laptop. This eliminates the expense and need of having to purchase different card adapters for the laptop. The Expansion Chassis is a dependable I/O expansion solution.
and this PCI only so any card will likely be l8imited to 1600/1200 in digital but can run higher resolutions in anolog
http://www.amazon.com/StarTech-com-Express-Four-Expansion-PEX2PCI4/dp/B000UZL1GC/ref=pd_cp_e_1
I would have thought that hooking up a graphic card to a PCIe slot is just a cabling and enclosure job -almost a DIY job - as confirmed by the prices of these assuming they work, but maybe the high price of digital Tigers and Vtech products suggests there is more to it than that..............