The Slashdot question about this topic reminds me of the overwhelming array of 9 chargers and low voltage power supplies which power my equipment.
In the comments, it was mentioned that a connector manufacturer employs a lobbyist to foil any attempt to mandate standardization of the connectors and low voltage power supplies.
Another comment mentioned the 12V standard car cigarette lighters. This standard is currently usable only in cars, and most gadgets are not designed to be powered from them.
- Manufacture a splitter which allows 5-6 plugs (shaped like car cigarette lighter plugs) to receive power at the same time. Those splitters are meant for use at homes, and will allow several gadgets to be powered/charged at the same time.
- Manufacture a DC to DC converter for each gadget, to allow most gadgets to be powered from standard car cigarette lighters. It may be possible to miniaturize those converters, as they don’t require a 110V/220V step down transformer. People will prefer to carry those converters with their gadgets, rather than the bulkier manufacturer-provided power supplies.
- Manufacture a car cigarette lighter lookalike socket, powered by a step down transformer, for use at homes. This will allow homes to provide the same power connectors as cars.
Then, car cigarette lighter sockets will become the de-facto standard power supply for gadgets. Those three products will solve the chicken-and-egg problem of introducing a standard power supply for gadgets, which require DC power.