Ubuntu-tweak was always a neat little application to fine-tune your desktop settings. The latest version is now a Swiss-army knife which goes a lot deeper into the guts of Ubuntu.
In addition to opening up Compiz and desktop settings, window manager controls (buttons on the left now folks!) and change security settings to lock down your desktop, you can change your software sources list, run updates, run package cleaner to take out redundant packages...
It's not that you can't do all these things by other routes, it's just that Ubuntu-tweak puts them all in one place, without recourse to a terminal session.You could argue that it duplicates some functions that sit fine where they are; will I update software sources from here? No. Do I know why the #### I should go to the Application Centre inside U-Tweak? No. But then I know Synaptic.
It still does its' original job very well and you could get seduced by the clear, shiny interface which does look like the software equivalent of an exhibition show-home; a very pleasant space to browse around and tinker.
Its' not in the official repositories so you need to go get the .deb package from http://ubuntu-tweak.com/.
Warning: Ubuntu-Tweak gives you so many settings to play with you can seriously drop your system in the sticky stuff. Don't change a setting unless you know what it does and how to undo it! RC