Project Thigh Master is a system that alleviates this condition by assuring that reminders to save electricity will not go unnoticed, increasing its owner's peace of mind by setting a penalty for environmental waste.A bit extreme, but a cool concept. Personally I would go for a colored orb or a piece of jewelry, but to each his own.
The system consists of a personal techno-garter -- inspired by the Opus Dei cilice popularized in Dan Brown's Davinci Code -- worn on the thigh, communicating wirelessly to a set of low-power sensors measuring the wearer's personal energy consumption. If the wearer's electricity use exceeds a certain limit, the device plunges stainless-steel thorns into the wearer's thigh, a reminder of their complicity in the planet's demise, and perhaps their own mortality.
Thigh Master aims to balance comfort and discomfort in a meaningful way in order to achieve sustainable change. Packaged in the form of yet another personal electronic device, the system helps people to break out of inefficient consumption patterns. But in addition to decreasing a user's energy use, Thigh Master can also provide relief for the less easily measured -- but no less real -- feeling of individual powerlessness in the face of accelerated climate change
I also think another cool take on this would be to substitute it for the vibrate mode on a mobile phone. Well, not a painful version (and I read a review that this implementation isn't actually painful) but one that just presses on your skin as a means of notification. Build it into a watch or a bracelet with Bluetooth and I think you have something. If you knew Morse code it could even be used as a secret way to receive messages.
via Thigh Master via Year In Ideas