SpaceSniffer is a freeWare (or, better, donationWare) and portable tool application that gives you an idea of how folders and files are structured on your disks
SpaceSniffer is certainly one of the more attractive and fun to watch applications around. Upon launch and when a drive is chosen SpaceSniffer goes to work. As it does its analysis colorful (colors are configurable) rectangles appear in relative sizes creating a percent by percent 2 dimensional picture of the drive being analyzed.
Files and folders are given different colors as are free and unknown spaces. The latter 2 are excluded in the default analysis but that can be changed of course. If the program is left open while other changes are made to the system the affected folders are highlighted briefly. Single and double clicking a rectangle gives more information as it zooms to show a more complete picture, that is its subfolder(s) and contents, of the folder being clicked on. It is also possible to filter the whole drive or any other view for a more specific mapping of the analysis. For example by typing “<3months” (without the quotes) in the filter box only files that are less 3 months old will be shown.
SpaceSniffer runs on Windows 2000, XP and Vista and is a very useful 871KB zipped download. The download also includes a Quick Start PDF.