These programs have been around for years. Spacemonger for Windows (http://www.sixty-five.cc/sm/ http://www.sixty-five.cc/sm/), Disk Inventory X for OS X (http:

These programs have been around for years. Spacemonger for Windows (http://www.sixty-five.cc/sm/ http://www.sixty-five.cc/sm/), Disk Inventory X for OS X (http://www.derlien.com/ http://www.derlien.com/), and a particularly groovy one for Linux with a 3D treemap circa 2001 (http://fsv.sourceforge.net/screenshots/ http://fsv.sourceforge.net/screenshots/).