Folder Size for Windows XP

Rather than just complain about how Windows XP does not calculate folder sizes like Mac OS X does, I decided that someone, somewhere must have done something about this already. It turns out they did. Click here for a nifty little tool to show folder sizes along with file sizes in details view.
In case you're wondering (as I'm sure my DW will) why I would even bother with this, it helps to know how big folders are when I'm cleaning out the hard drive, looking for junk to throw away to make more space. This is an issue because I run XP on a 10GB partition of my MacBook and Windows is such a bloated disk hog. Oops. I was going to try to not bash Microsoft, but I guess I just couldn't make it...