If you want to tweak Ubuntu I would suggest that you should try Ubuntu Tweak 0.4.4. It is easy to use with a simple user interface and you can get things done without much hassle.
I wanted to change my icon beside the Applications menu so I used Ubuntu Tweak I changed it to a smiley face which has a great big toothy grin. That was one of those things that will make a hassle about which size of a picture you can have… which is 24×24.
Also you can change security features like: Disable ALT-F2, Disable Lock Screen, and a couple more. I would use this to change a couple more things if it had the features… 1)change panel height 2) change themes. Those are a couple of things that could be put into this program.
I love this program and it is getting better by the release. To download go here which i s for the 32bit Intrepid Ibex (Ubuntu 8.10)