Windows 7 introduced some really nice features for positioning windows on your desktop by just dragging things to different edges of the screen. It's something that most Mac users should feel very jealous about.
There is a way to add similar functions to your Mac, and one is a great piece of software called SizeUp.
This gives you a wide range of keyboard shortcuts to instantly push application windows to specific parts of your screen. You can make a window take exactly one quarter of the screen, or you can make a window jump across multiple monitors. You can make windows maximise, or go to the centre of the screen, and you can tweak exactly what each command will do when it resizes your windows.
Very handy, and free with a few nag messages, or all yours for just US$13.