Multiple monitors and multiple desktop support with Windows

Hardware multiple monitor support

DigitalTigers product called SideCar that lets you run as many as four external monitors from your laptop. You end up with a huge desktop display and still have the mobility of a laptop.
* http://pcworld.about.com/magazine/2004p150id81963.htm - Double screen space

Software multiple monitor support

Windows Dualview function
http://www.maxivista.com/ - use a second machine as a monitor for your primary PC. Can also function as a KVM to control multiple machines from a single machine, and can be used to clone the display of one PC to another over a network.
- Reviews:
  - http://graphicssoft.about.com/od/productreviews/gr/maxivista.htm
  - Using multiple monitors with Windows XP - http://www.microsoft.com/windowsxp/using/setup/learnmore/northrup_multimon.mspx

Managing multiple desktops