I put up LED Christmas lights last December, after calculating that they would pay for themselves after just three Christmas seasons through savings in electricity.
Now some hardware stores are selling LED desklamps -- pricey, but again there is the promise of electricity cost savings over the long term.
I got a cheap version at London Drugs. From Logiix, for $15. It's a 10 LED lamp that plugs into a computer's USB port. I often work early mornings and late evenings, and I though this might be good for providing illumination of the keyboard.
I don't use it anymore. Here's why:
-- no On/Off switch. That means plugging it in and out of the USB port, or else leaving it turned on all the time.
-- slightly too weak flexible neck. This meant it was hard to adjust exactly into place, and tended to droop.
-- but worst of all, it made my head go wierd. I wonder if ten bright white LEDs affect the eyes, which then leads to other head problems, like headaches and so on.
The exercise did lead to an interesting question: If I plug LED lights or other deviecs (like my Palm TX for charging) into USB ports, does the computer draw more current from the mains? Or do I get this electricity for "free"?