It's funny, I also thought about Emergency Medicine about third area (after programming and military) where you need to solve real problems quick for living. So try it, if you are inclined.
Another area is Daytrading or DayGambling, but now is obvious why to avoid it... ;-)
If money are not an issue, and you want to feel good what you are doing, you may want to help some non-profit organization. I can tell you, it's very rewarding...
To make errors is human. But to make million errors per second, you need a computer.