Not a complete solution, but I was able to make a pedalboard power adapter using one of those usb car chargers. The chargers have a built in regulator to convert 12V into 5V, and it seems that a 9V input works fine, too. Enclosure is a plastic project box I got when RadioShack was going out of business. I'd love to say I came up with the car charger idea myself, but I came across it elsewhere.
This doesn't solve the inherent weakness of the mini-usb, but at least with a small right angle mini-usb adapter it reduces the opportunity for damage.
Hope it helps somebody.
First, here's the car charger. Connect a wire to the central tab (positive) and a wire to one of the two ground tabs.
Next, reassemble the car charger, and mount it in a box along with a standard 9V receptacle. The charger is held in place by two screws.
End result: 9V to 5V pedalboard power supply adapter. I still need to get a short right angle mini-usb cable to put this on my pedal board.
