Besides editing the menu.xml to customise the menu, why not install wbar and edit /usr/share/wbar/dot.wbar to add convenient quick launch icons to the wbar dock for the most commonly called upon apps. It’s even simpler than editing the menu.xml file, especially if you use vi.
My desktop is quite nicely themed and as conky shows, is very light on resources.
conky – the monitor on the left hand side of the screen can be customised by editing .conkyrc in your home directory. To install it, simply type sudo apt-get install conky then get hacking.
To effect the changes, simply right click on wbar, or restart the conky process using kill -HUP