I fly bigish (>4m) rockets for fun (check this out).
I have an old company on the side called Taniwha Systems Design which doesn't do much for me these days - other than get me free magazine subscriptions, but we used to use it to sell Mac serial cards - we stopped when my first child was born, he's left home now. (We never intended to use the name for other than collecting royalties and when we had to start trading under it no one here could pronounce it). Recently I put the name on a not-for-profit open-source flight computer kit I've been building.
Usefull stuff (at least for me):