We designed a basic 4-Port USB Hub using the inexpensive FE1.1s IC. The basic reason is to use one of the Raspberry Pi's built-in USB ports to add 4 USB ports that are easily accessed from outside an enclosure.
Using a short (6in.) USB micro-B to USB-A cable we'll connect this USB Hub to one of the Raspberry Pi's ports. For now, we'll be powering the Hub directly from the USB port of the Pi as we don't intend to draw too much current from the hub output. A separate port from the Pi will be used for running any other USB device (in our case, we'll only need one for a Wi-Fi adapter).
Caveat emptor: we'll have to test this arrangement using 4 wireless controllers, which need the USB Bluetooth Adapters and may draw too much current from the single port of the Pi.
The design files are up on Github: https://github.com/acrobotic/Ai_Hub_USB