Baobab

Disk Usage Analyzer is is a graphical, menu-driven application to analyse disk usage in any Gnome environment. Disk Usage Analyzer can easily scan either the whole filesystem tree, or a specific user-requested directory branch (local or remote).

It also auto-detects in real-time any changes made to your home directory as far as any mounted/unmounted device. Disk Usage Analyzer also provides a full graphical treemap window and a ringschart for each selected folder.