Ever find yourself asking, "Where's all my hard disk drive space gone?", and even more so, "Which application has stolen it?!". Well, guess no more... I came across this really handy free application called WinDirStat (you can download it from here), that let's you see you whole hard drive visually. Here's a snapshot of my hard drives at home:-

WinDirStat

Cool, huh. Previously, I've been using an internal tool at Microsoft (which one of our employees wrote) called FatSlice. Once again, here's a shot of my hard drives at home:-

FatSlice

Alas FatSlice is only available to Microsoft employees, but WinDirStat is available for everyone! :-) Go check it out.