Trainspotting (I even considered a quadcopter for shooting videos). Roller skating. And posting food photos on my blog before eating.
Senior Networking Infrastructure Architect. Basically, that Grey Eminence who makes your internet working.
Building weird machines using only LEGO bricks.
Undecided: a laser cutter or a 3D printer...? Bo(t)h.
Ubuntu, both Desktop and Server versions, altough I prefer Arch Linux for my BeagleBoard flock.
A number of tools are always on my desk. USB-to-TTL adapters, a Dremel tool, a battery-powered 1W LED to light up small details, a digital multimeter, a bunch of battery chargers.
My last two ones were the NEC V20 and the Zilog Z80. I've never been too much enchanted by 32+ bits CISC beasts.
Ruby. I just stopped using everything other (both compiled and script) because of Ruby. I can't even remotely imagine a better language. I only touch some C++ for a few rare bizarre cases.
I'm going to mention only the simple ones:
1. Flying on a machine built by myself.
2. Running Ruby on a Linux machine using a CPU designed by me.
3. Building a fully working mecha out of LEGO parts.
Skill: Ruby programming.
Concepts: order of magnitude, dimensional analysis, NP-completeness.
I would like to learn Russian language. Tough. Help needed.