No idea if this is any good but it seems like a good idea. It's software that let's you use your notebook computer as a second monitor. Of course it's not as fast has having an actual second monitor but if you have an old notebook sitting around not doing anything it might be a great way to get some extra screen real−estate.
I didn't have a chance to try it myself since I actually use my notebook but still it sounds like a good idea.
Having 2 monitors at work I can tell you it's extremely useful to have 2 or more monitors. Some studies stay you can get as much as 30% more efficient with 2 monitors and I for one believe it having given it a try. As soon as I can afford it I'll do the same at home.
While we are on the topic, something many people don't know, most modern graphic cards support using a TV as a second monitor. TVs don't have the resolution to be useful for most applications but they are useful for watching video. Plug in the TV, reboot your computer and go to the display control panel to turn it on. Once on, setup it's resolution, then start Windows Media Player, drag the player over to the TV and double click the middle. It will go full screen on the TV.