If you have 16 devices that you need to charge simultaneously via USB, I'm going to stick my neck out and say you have a problem. But at least it's a problem with a solution: this 16-port USB charger is just what you're after.
This is the Datamotion Systems PowerPad Charging Hub, and it's a monster. Look at all those USB ports, and all that potential charging. Oddly enough, the company claim it's "designed for charging Apple devices" but you'd obviously be able to charge whatever you damn well like with it as long as you can shove a USB lead into it.
Perhaps not the most essential piece of kit for every household, admittedly, but if you have a (very) large family it might prevent squabbles over chargers. Or, perhaps more likely, it would be pretty handy in an office or classroom.