From SB Software:
This free user-friendly utility helps you visualize which programs on your hard drive are using too much disk space. It creates a navigable pie-chart visualization of the space utilization on your computer. This utility is a great helper for situations when you get one of those messages from windows letting you know that you've run out of space, and wanting you to do something about it. This program will help you determine what is using too much space. Version 1.5 may include unspecified updates, enhancements, or bug fixes.