Ubuntu Tweak is an application designed to config Ubuntu easier for everyone.It provided many usefull desktop and system options that the default desktop environment isn’t provided.At present, It is only designed for Ubuntu GNOME Desktop, and often follows the newest Ubuntu distribution.
Features of Ubuntu Tweak

* View of Basic System Information(Distribution, Kernel, CPU, Memory, etc.)
* GNOME Session Control
* Auto Start Program Control
* Qucik install common usded applications
* A lot of third-party sources to keep application up-to-date
* Clean unneeded packages or cache to free the disk space
* Show/Hide and Change Splash screen
* Show/Hide desktop icons or Mounted Volumes
* Show/Hide/Rename Computer, Home, Trash icon or Network icon
* Tweak Metacity Window Manager’s Style and Behavior
* Compiz Fusion settings, Screen Edge Settings, Window Effects Settings, Menu Effect Settings
* Set the Shortcuts to let qucikly access your favourite applications
* GNOME Panel Settings
* Nautilus Settings
* Advanced Power Management Settings
* System Security Settings
Install Ubuntu Tweak
Option1:
open your terminal, first import the key:

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

Use this command to edit the sources.list:

sudo gedit /etc/apt/sources.list

add following into the file,then save and close it.
For ubuntu 9.10:

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

For ubuntu 9.04:

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

For ubuntu 8.10:

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

For ubuntu 8.04

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

Now,update and install this:

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

Option 2:
Visit to this link to download the latest package and source code:
https://launchpad.net/ubuntu-tweak/
Old version of Ubuntu Tweak is available here:
http://code.google.com/p/ubuntu-tweak/downloads/list
Screen shots
ubuntu-tweak

ubuntu-tweak1

ubuntu-tweak2