Do you want to easily work between two windows simultaneously? Maybe you just need more desktop space? If so, Twinsplay might be useful.
When installed and running, it adds an icon to the system tray, new hotkey commands and a mouse center button menu. The first function can move your window to the left or right, resizing it to take up half the screen, you can then do the same for a second window on the other side, to have your screen. Working in one window while reading from the other is made really easy.
The second feature is adding a desktop. You can move any window to desktop 2 or 2, and move quickly between the two. This is great for people who have tons of windows open at once, but want to reintroduce some calm to their desktops.
Twinsplay is a neat way to manage and add space to your desktop. It's easy to use, and even the hotkeys are intuitive. We had some problems using old programs in XP - they didn't always respond to Twinplays commands.
Twinsplay offers two nice functions of a second desktop and windows management, and executes both well using little resources.