Indicator applet for displaying and changing CPU frequency on-the-fly. It provides the same functionality as the Gnome CPU frequency applet, but doesn't require Gnome panel and works under Unity.
Install CPU frequency applet on ubuntu 11.04(Natty)
Open the terminal and run the following commands
sudo add-apt-repository ppa:artfwo/ppa
sudo apt-get update
sudo apt-get install indicator-cpufreq
Create unity launcher
You can create unity launcher using the following procedure
Right click on desktop, select "create launcher" name it, icon it, and put "indicator-cpufreq" as the command. then drag it to the unity launcher.