OK, Here is the full procedure for Installing a Theme in Ubuntu.
Method - I
For eg., Here I give the procedure to install the MacOS-X Aqua Theme
Download it from here
You need to download 3 files.
1) 13548-Gnome_MacOS-X_Aqua_Theme_20040730.tar.gz
2) Gnome_MacOS-X_Icon_Theme_20040730.tar.gz
3) MacOS-X_Aqua_Wallpapers.tar.gz
After you have finished downloading all 3 files. Let's install them!!
Open the Terminal Window & type:
$ gnome-theme-manager
This will open the GNOME Theme Manager.
Now, click on the 'Install Theme' button on the top-right, In the 'Theme Installation'
dialog , click on 'Browse' button & choose the file '13548-Gnome_MacOS-X_Aqua_Theme_20040730.tar.gz' .
Click on 'Install' button.Now the Mac Theme will be installed. Now select 'MacOS-X' Theme(Just scroll down a bit, you'll find it!!).
Now extract the 2nd file 'Gnome_MacOS-X_Icon_Theme_20040730.tar.gz'.
To extract it, right-click , 'Open with Archive Manager' Click on the 'Extract' button.
A 'Extract' dialog appears, again click on the 'Extract' button. Close the 'Archive Manager'.
Now you'll find a directory called 'MacOS-X' . You must move this directory to the
'/usr/share/icons' directory. To do that, type & execute the following command:
$ sudo mv MacOS-X /usr/share/icons
NOTE: You must be in the same directory were the 'MacOS-X' folder is stored. Use
'cd' command to move to that directory.
The final part, extract the 'Wallpapers' in the file 'MacOS-X_Aqua_Wallpapers.tar.gz'
And set the Wallpaper. That's all.This is how you install a new Theme in Ubuntu.
Ubuntu using Mac O.S Theme!!
*img210.imageshack.us/img210/3221/macthemewf6.th.png
Method II
$ sudo apt-get install gnome-art
You can choose the Theme, preview it & install it if you like!!
It's very much easier!!!!!