Windows provides only limited Window arrangement facilities by default. The usual Tile Vertically, horizontally, cascade windows are the usual options available in Windows. But it was never flexible to use, especially with multiple monitors.
In Windows 7, as part of the Desktop Enhancement new Window Organizing features are more flexible than ever. Like maximizing, horizontal, vertical resizing, side by side view etc.. The best thing is it’s integrated with keyboard shortcuts and also with some cool mouse gestures. e.g by dragging to the top edge, you can maximize the window, to the right or left edge. you can make it 50% size vertically to make a side-by-side comparison. also you can do these with Keyboard shortcuts as well.
But, Windows 7 is yet to be released. Also not everyone opting Windows 7. This kind of simple features are really handy especially when you’re using a high resolution display and multi-monitor setup.
WinSplit Revolution is a free solution for excellent window management for high resolution and multiple monitors. It permits you to "divide" your screen into several parts: halves, thirds, fourths, etc… For instance, a window can be resized and moved to the left half, the right half, the top, a corner… of the screen. Also it helps you to move a Window to another screen when you’re using multiple monitors.
[Image taken from http://www.winsplit-revolution.com/]
The utility provides some cool features as (don’t confused with the name, take the help page and try each features you will find it very easy). Also Video Demo will help you for an introduction
- Automated window handling (resize, move, reorganize, close tasks)
- Shape – process association
- Global hotkeys and clickable virtual numpad
- Automatic startup
- Automatic update
- Moving a window with mouse (drag’n'go)
- Hotkey configure
- Layout configure
- Fusion between 2 windows
- Minimize/Restore by hotkey
- Mosaic mode
Enjoy this cool utility with your own desktop for painless arrangement of Windows @ free of cost.
In my case, usually use this for dealing windows with multiple monitors and side by side view (for updating review comments 
). Also resizing my Google reader windows to 50% horizontal for painless reading 
and lot more.