This tutorial is about how to configure your Unity to get transparent top-panel and window title bar. I did following in Ubuntu 11.10 Oneiric with Unity desktop.

1.) Get the transparent top-panel.

Unity’s panel opacity is controlled by Ubuntu Unity Plugin under CCSM. So to do that first install CompizConfig-Settings-Manager by following command in a terminal window:

sudo apt-get install compizconfig-settings-manager

Then launch CCSM. Click to go into Unity Plugin’s configuration page, in Experimental tab change the value of Panel Opacity.

2.) Get transparent window title bar

First, run this command to install compiz-gnome and gconf-editor:

sudo apt-get install compiz-gnome gconf-editor

Press Alt+F2 key combination and run gconf-editor, then navigate to apps/gwd.
In right, change the value of “metacity_theme_active_opacity” and “metacity_theme_opacity” range from 0 to 1.