1) One millimeter higher:
Use 4 male header plastic bits. One for each of the 4 corners of the protoshield
This way, the protoshield stands a little higher than standard
But the benefits are great: You don't have to worry about shorts with the USB connector anymore.
Safe distance. At the same time, the protoshield is so much easier to plug and unplug now.
2) An LED tester
I don't use the BlueSmirf socket. But I connected the female headers because it provides an extra +5 and extra GND for prototyping.
With a single 300 Ohm resistor between GND and the centermost pin (originally unused in the Sparkfun protoshield, you will be able to use the two centermost pins to test any led: Very handy!!!
3) A Power LED on top
If you add a resistor to +5 and an LED on top will serve as a Power LED on top of the protoshield. This is very handy to make sure your system is powered: