Challenge: Build a simple and cheap mod which allows you to transmit USB signals over bluetooth. Or Heck, I don't care how it's done, but something that allows me to plug in a couple wired USB devices to a little dongle that wirelessly tx's/rx's data to a receiver on the other end that makes the devices appear to be their USB selves on the other end.
Cables Unlimited used to make something like this: http://www.amazon.com/Cables-Unlimited-Wireless-Transmitter-Receiver/dp/B0036VNZHA But they are OOS and hard to find.
This is especially important as Virtual Reality devices start to come to play- Bonus points if it can transmit HDMI.
YOU HAVE BEEN CHALLENGED!