Use your keyboard to move and resize windows in an easy and frictionless way.
Download a free trial version at http://windozerapp.com
Windozer aligns windows to a grid when you move or resize them, which means that you don't have to spend a lot of time fiddling with pixel-precise positions and sizes.
What you can do:
Move windows - Hold the move keys and press an arrow key, and the current window moves in that direction.
Resize windows - You can resize a window from any edge. Hold down the resize keys, then press an arrow key to choose which edge of the window to resize from. Then, use the other arrow keys to resize.
Stretch windows - Stretching is a combination of moving and resizing. It makes a window to take up a customizable amount of the screen in the direction of the arrow key you press.
You could have a large amount of space set for the left side of the screen for a web browser or text processor, with a smaller chat window or PDF open on the right.