Just thought I'd let you know about TreePie.
I've been having some problems with certain departments eating a lot of space and treepie has been invaluable in tracking down what space is used where.
Basically you give it a directory and it gives you a pie chart of the contents. Showing you which folders contain the most data. Beats right clicking until you find the culprit.
TreePie | Download TreePie software for free at SourceForge.net