GNOME disk usage analyzer
Disk Usage Analyzer is a graphical, menu-driven application to analyse disk usage in a GNOME environment. It 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 for each selected folder.