I launched my project ArduinoPixed on Kickstarter - it adds 3 USB ports and an on board Arduino off the 4th USB port of the Hub. All this using just 4 Mounting holes. None of the 40 Pin connectors are used and these are available for anything that users may want to do.
The details can be found on kickstarter here - https://www.kickstarter.com/projects/17 ... r-pi-zero/
This is a topic worth covering in MagPi. I have couple of Rev A boards that I can give out if required to get into details of it. This is a sequel to my popular Hubpixed project - the first of its kind Hub for Raspberry Pi Zero.