Wattson

If you've been thinking about cutting back on your electric usage to help save money (and the environment), then you'll want to check out Wattson (£100; ~$180). This wireless gadget uses a sensor chip and transmitter attached to your main electric cables to monitor your usage, with the main unit glowing blue when your use is below normal, purple when usage is normal, and red when you're using more than usual — which is normally too much. Plus, the main display shows in watts or in currency how much electricity you're using, giving you immediate feedback, and even more motivation to conserve.