You forgot to include trolling (and not very good trolling, I might add).
The keyboard is mightier than the gun.
Non parit potestas ipsius auctoritatem.
I could tell all the cool hobbies I have, but that is in fact uncool, so I will tell you the nerdiest hobby I have:
Apart from economics, it's watching Starcraft 1on1s commentated by HuskyStarcraft on YouTube.
More seriously, I party on the weekends like Daniel Muffinberg. Otherwise, I like to read, write computer programs, post on internet forums, and work out at the gym.