On the BBC Click programme on 20080711 they mentioned an "Energy saving charger" for mobile phones.
It's a plug in phone charger that only uses power when there is a phone connected to it.
It works by having a switch that is activated by the weight of the phone - no phone = no power.
Sounds like a great idea, but is it?
In computing there is a saying "We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil."
Which basically means, measure the problem and attack the worst bit, as it may not be the bit you thought it was.
I've measured the power usage of a mobile phone charger with no phone attached, using a power meter between the device and the mains.
It was 0W.
The Phone chargers - the truth website found the same -
My measurements indicate that my phone chargers consume less than 0.5W when left plugged in. The total power consumption of the average Brit is 5000W. (Including car driving, home heating, and so forth, not just electricity.) So obeying the BBC's advice, always unplug the phone charger, could potentially reduce British energy consumption by one hundredth of one percent (if only people would do it).Mobile phone chargers are not a major contributor to energy waste.
Don't waste your money on an "Energy Saving Charger".