When I ran Fedora on my laptop, I loved how I could manually set the CPU speed in Gnome using the “CPU Frequency Scaling Monitor” applet.  I noticed that I could not do this under Ubuntu (you can monitor speed, but you can’t change it). It’s actually a feature, not a bug.  In order to change CPU frequency, the binary needs to be SUID, which Ubuntu doesn’t enable by default.  In order to change this behavior, run the following: sudo dpkg-reconfigure gnome-applets

Answer “Yes” to the question regarding cpufreq-selector.  You will immediately get the ability to change your CPU frequency - no reboot, no restart of Gnome, not even the applet needs restarted!