I found this device for laptops which do not have dual screen support.
From Mergi
http://www.margi.com/products/prod_dtg.htm
Cost starts from a $149.00 from the US although they may have a european distribution I did not Check.
It has alot of features
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Features
Multiple Displays
Multitask faster and increase the virtual size of your desktop by adding additional displays to your notebook PC. You'll be able to see "the big picture" more clearly with the ability to control several displays through a common desktop location.
Typical Applications
Connect multiple LCD displays to provide a seamless display - save space
Give a PowerPoint presentation, while simultaneously, viewing notes on the laptop
Track HTML code on one display and Web page content on another.
Compare multiple versions of a layout, graphic, or design from different displays.
Create a panoramic view of a large or very detailed spreadsheet.
View stock quotes on the Internet on one display while analyzing financial data on the other.
Station conference attendees at different displays and conduct a Microsoft® PowerPoint 2000® presentation from your computer at the front of the room.
4MB RAM, 64bit Graphics - upto 1600 x 1200 resolution
4MB Graphics RAM lets you work at a resolution upto 1600x1200 and 16bit color. In addition to providing a larger working area, the Display-to-Go 4MB card also keeps your presentations jitter-free.
Non-Standard Resolution Support
Some LCD displays work at resolutions that are not VGA standards. DTG makes it possible to support these devices.
Plasma Displays with "letterbox" or "16 x 9 format" resolutions.
Apple Cinema at 1600 x 1024
Silicon Graphics 1600SW which runs up to 1600 x 1024
Complete List of Supported Resolutions
DVI, DFP and VGA Interfaces
Increase your productivity. Remove your compatibility worries. The same Display-to-Go 4MB card can be used with the VGA, DFP and DVI adapter cables to plug into analog or digital displays including Apple Cinema displays..
MacOS Support
Our commitment to platform independence remains strong with support of MacOS 9.1 powerbooks. This includes support for both Studio Display and Cinema display with DVI connectivity*.
* New Cinema displays featuring the ADC connector can be connected using Dr. Bott's DVIator. DVIator allows the use of Apple's ADC flat panel displays on any Mac with DVI video.
Desktop Management Features
The desktop management software increases your productivity through hotkey support for quick information access, drag-and-drop application positioning & stretching across multiple displays.
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Cheers
Edd