For laptop users, this may interest you: PowerTOP got a major version
bump to 2.0, featuring a major overhaul of the code and new tabbed interface. They also now have a new homepage, at
https://01.org/powertop/ (among other Intel open source projects.)
I got this new version building with Pat's 1.13 SlackBuild, changing it by the addition of a './configure' invocation; the new powertop needs a manpage though.