Ever since I got my first Raspberry Pi (and before; I never did anything with battery-powered applications for the Beaglebone but I certainly had some in mind) I've been thinking about putting them out in the world.

There’s little doubt about the question of efficiency: linear regulators are less efficient than switching regulators. Though I have no doubt that someone can find an example of a very efficient linear regulator that is more efficient than a poorly-designed switching regulator, such an example would be a rare