WinSize is a template for screen sizes. It is a white frame showing the most standard screen sizes, from 640x480 up to your screen definition.
(640x480, 800x600, 1024x768, 1280x1200, 1280x1024, 1600x1200), portrait and landscape.
You may use it to quickly adjust the size of your navigator window and see how that wonderful Web page of yours renders on different screen resolutions.