Aerofoil extends your Windows laptop battery life by automatically switching power profiles

I've got an old Toshiba laptop. It's a workhorse, and I take good care of it. But as a laptop ages, one thing invariably happens: Battery life grows shorter and shorter. It's a matter of chemistry, and no amount of prudency seems to keep it from happening.
So as your laptop ages, intelligent power management becomes increasingly important. The question is "how do I keep this thing from hogging so much battery when it's not connected?"
Sure, Windows has built-in power profiles; but for some reason, right-clicking the battery icon only shows two profiles (out of the three default ones), and somehow that list never includes the particular profile I'm trying to switch to (I have four profiles).
Aerofoil is a free application that strives to make the power-saving process painless. It's one of those things that should have been built into Windows in the first place: As soon as your laptop switches to battery power, Aerofoil switches the power profile to Power Saver. Plug the laptop back in, and Aerofoil switches you back to High Performance (or whatever you've got configured).
But wait, there's more! (Cue cheesy infomercial music) Aerofoil also switches off Windows' Aero Glass interface whenever it switches to Power Saver mode. It can also automatically mute the sound when you switch to battery mode!
One note: When you first run Aerofoil, your computer may pop up an error message about msvcp100.dll. In that case, you need the MS Visual C++ redistributable, which you can grab from Microsoft for free – both for x64 and for x86 systems. Enjoy!