If you design or tests websites, then you have to make sure they work in different screen resolutions. You have to change the size of the browser window or maybe even change the screen resolution. There are tools that let you resize the window to different predefined sizes, like the Internet Explorer Developer Toolbar or the Web Accessibility Toolbar.
The link toolbar with resize buttons
The link toolbar with resize buttons in their own folder
You can then add another favourite and call it 800x600 or whatever screen size you want. It’s quick, simple and easy to customize.