Disk Usage Reporter is a perl script designed for monitoring disk 
usage in a more visual way than du. The du program works fine but
doesn't allow a lot of control over how the results are displayed.
This perl script is designed to produce output more useful for
reports.

Although durep can produce text output similar to du, its real 
advantage is that it allows you to navigate through the directory 
structure as web pages.  Each page shows bar graphs for entries so it
is easy to see immediately which directory is using the most storage
space. The report generated can be configured in several ways (hiding
directories, collapsing directory entries, hiding entries below
certain sizes, etc).

The text report that durep generates is also configurable. You may 
limit the depth to which it displays entries, allowing a quick
non-detailed view.

WWW: http://www.hibernaculum.net/durep/