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 any thing 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.