I have been useing this free program called Sequoia View for a few weeks now. Basicaly it gives you a visual picture of how much space files and folders are takeing up. It is unique from other simular programs I have tryed as instead of listing files and the corosponding size, you see colored areas instead. The feature I like most about it is the ability to change the color scheme.

You can assign colors to various file types such as yellow for zip files. This way you know anything yellow is a zip file. I find this is a very handy tool for locating unessary junk files, and just keeping general maintence of your hard drives.

Out of all the simular tools I tryed I give this one a 10 out of 10.

http://www.win.tue.nl/sequoiaview/