I like to play computer games on my spare time. I find that first person shoot'em-up games improve my ability to deal with stress and to make rational decisions fast. Whereas strategy games develop my overall reasoning, problem solving and planning skills. World simulators and role playing games add entertainment value to the previous categories.
When I was younger, I had a lot of pet software projects as a hobby. Now that I have a day time job in the ICT sector, I'm not as willing to do that on my spare time anymore.