I have relatively few hobbies; I think of it as putting more wood behind fewer arrows.
First and foremost, I love solving problems and coding is something that lets me do that. Composing algorithms and solving puzzles gives me a sense of satisfaction. Working on a problem for hours and eventually figuring it out is such a great feeling.
I'm a huge Android fanboy. I love everything about it from the platform, api's and development style to the design asthetic and interaction design of the interface. I follow the operating system very closely and I always try to keep up with the trend of development. I also try to keep up with the hardware and always have the high end developer phone.
One of my newer hobbies is a blend of user experience, information architecture, interaction design and graphic design. I'm trying to make a career out of being a developer and a user experience designer. I've had an internship designing user interfaces and I really enjoyed it. I design apps in my free time and I use my developer roots to actually implement them. My latest project is a gesture based music player.