I do not know if I posted this before but I'll post it now (again?). It is how to connect your Raspberry Pi Zero to your PC's USB Port and have full access to it. Though there is some hardware mod to this to make it look cute, it is not necessary and you can use a USB to USB Mini cable to connect the two. The rest of the mod is mostly software.
 
This should also work with the other Raspberry Pies and other Pies as well, since the hardest part is the connection and the rest is just software. Thus a nice Quad Core system as in the Orange Pi or even Octa Core Nano Pi can be used like this as well!
 
A couple of How-To-Videos:
https://www.youtube.com/watch?v=wUNPiCfCUzI
https://www.youtube.com/watch?v=OU9e3jIqaBY
https://www.youtube.com/watch?v=4gLzJGrkfVw
https://www.youtube.com/watch?v=aL1pWI2K60w