Ubuntu-Tweak is a great ubuntu utility that has a strong functionality such as add and remove apps,edit sources/third-party sources,free up disk space by removing unneeded packages,configure auto-start apps,configure desktop icons,windows,Compiz Fusion and gnome things and so on.
By now,Ubuntu-Tweak has release version 0.4.9.2.Here shows how to install or upgrade the latest version from PPA source.

Step1:open your terminal,import the key:

sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com FE85409EEAB40ECCB65740816AF0E1940624A220

Step2:type the command to run gedit(or other you favourite editor ) to modify the sources.list:

sudo gedit /etc/apt/sources.list

And put the two line into it(If you are using Ubuntu 8.04 Hardy or early) :

deb http://ppa.launchpad.net/tualatrix/ppa/ubuntu hardy main
deb-src http://ppa.launchpad.net/tualatrix/ppa/ubuntu hardy main

Or Ubuntu 8.10 Intrepid:

deb http://ppa.launchpad.net/tualatrix/ppa/ubuntu intrepid main
deb-src http://ppa.launchpad.net/tualatrix/ppa/ubuntu intrepid main

Or Ubuntu 9.04 Jaunty:

deb http://ppa.launchpad.net/tualatrix/ppa/ubuntu jaunty main
deb-src http://ppa.launchpad.net/tualatrix/ppa/ubuntu jaunty main

Or Ubuntu 9.10 Karmic:

deb http://ppa.launchpad.net/tualatrix/ppa/ubuntu karmic main
deb-src http://ppa.launchpad.net/tualatrix/ppa/ubuntu karmic main

Step3:Finally, update the source and install or upgrade Ubuntu Tweak:

sudo apt-get update
sudo apt-get install ubuntu-tweak

if you have installed, just type:

sudo apt-get dist-upgrade

Credit goes:http://blog.ubuntu-tweak.com/downloads