ELECTRONIC gadgets have changed a great deal in the past few years. Most obviously, they have become smaller, sleeker, smarter and more versatile. Billions of people now carry around tiny devices that are more powerful than the desktop computers of a few years ago. But these gadgets have also changed in a less obvious way. Once they were lumps of hardware, brought to life by a layer of software; today, they might be more accurately described as services in a box.