Folder Size
for Windows adds a new column to the Details view in
Windows Explorer. The new column shows not only the size
of files, but also the size of folders. It keeps track
of which folders you view, and scans them in the
background so you can see complete size of all files
within the folder. It's very useful for cleaning up your
disk. Once you get used to having that information
available, a directory listing simply looks incomplete
without it.