[dekhn]

I'm not a fan of that form factor (dual rows of pins on both sides), it's not super breadboard friendly (works ok in perfboard). But, I have just soldered in one row on each side which gives you Vbus, GND, 3.3V, and ~12 GPIOs (with some restrictions). You can draw a fair amount of current from Vbus for ancillary devices (I run a 16x16 LED panel through mine and can reach full brightness, sustained).

[jacquesm]

You can run the headers 'up' on one side and 'down' on the other if you need more access (you then still need to bridge from 'up' back to down somewhere else but at least you'll have the room to do so.