I'm hoping Microsoft add this functionality into the standard power manangement features of Vista at some point and this isn't needed anymore, but if they don't and the utility proves popular, I may add some other powersave functionality not currently available - although I don't know what yet, maybe options to disable sound, slow down gpu clockspeeds via atitool profile or similar!
GPL'd source code will be available shortly - I've not got time at the moment to bung in the relevant licence comments, readme and package up nicely. This should be in the next day or two.
Get Aerofoil here!
If you find this useful and want the new features please post a comment or suggestions!