I have a question. Consider serial cables and data cables for a moment. We have SATA, Ethernet, FireWire, USB 1.0, USB 2.0, PS2, Serial ports of all kinds of stripes, etc. Each of these has its own plug design, its own specification, and in many cases its own internal bus. In some cases, there are variations on the plug design: see USB. In some cases (I’m looking at you, hard drives), there’s a data cable and a power cable; in other cases they’re both in the same cord (USB, power over ethernet).

Why can’t we have just one cord with two or three plugs? Certainly the thing that would send information and power to a hard drive could do the same thing for your digital camera, your screen, your video camera, and your network. We could have on kind of plug for removable devices, another kind for semi-permanent devices, and a small version of both for compact devices.

Am I missing something here? Why can’t this be done?