Having recently installed the Zalman ZM-MFC2: 4 x Fan Controller + Power Meter in my Intel build below, I have to rave about this widget!
Not only does it control fans and look really pretty, the Power Consumption meter has me turning off my machine at night!
During system idle, the machine consumes about 155 watts of power. During CD/DVD burning it cranks up to 210 watts!
Not that we need another machine directing our lives, but this energy monitor feature is really handy. I wish it were more readily available.
I have to say, I will install one of these boxes in every build I do from now on!