Why "RMS watts" is a useless measure of power

As part of my campaign to eliminate wall-warts and external power supplies that don't have on/off switches, I've built a USB charger that has a mains switch. Why? Because nobody seems to sell one.

In a market dominated by the Amazon Kindle, it's easy to forget that Sony, not Amazon, made the first commercially-successful e-book reader.

How worried should we be, that we're wasting electrical energy for no benefit?

How a non-existent English village ended up on maps, and the implications this has for how we handle information.

The built-in cd command in the bash shell is not as smart as it could be; but it's a little fiddly to extend its functionality.