If you’re using a Mac, you owe it to yourself to try a great program called Divvy.
In a nutshell, Divvy lets you divide up your workstation as you see fit, without having to manually resize all the windows yourself. For instance, at work I have two workspaces; one for Mail and Calendar split 50/50, and one for Terminal, NetBeans, TextMate, and FireFox, with Terminal and FireFox taking the largest space. Manually positioning four windows without leaving gaps is nigh impossible, and time consuming to boot. I bind Divvy to Ctrl + Shift + Spacebar, and can position all 4 windows just how I like in just seconds.
Protip: Hold down the command key while dragging to get a finer grid.
Protip #2: You can set keyboard shortcuts for different divisions of the space. Press the little gear icon in the top right of the program and go to the Shortcuts tab.