Short on disk-space?

Interesting article on what to do when you surprisingly find you've almost run out of disk space.
This guy recommende the use opf xdiskusage which looks pretty good. However, I'm not sure it's any better than the disk usage anayzer (baobab).
In any event, he mentions one thing I hadn't ever thought about which is that you may have an awful lot of logs stored in /var.
So perhasp you can very rapidly get an awful lot of space back (he got 20 GB).