What other hobby or hobbies do you have?

My son and I are big into radio controlled models. Personally I think it's the best father/son hobby around. We're also into 1:1 size cars as well.

I don't consider listening a hobby, it is participation in an art. Hobby denotes a light interest to pass the time, like watching sports.

Hiking and photography. Use Nikon D300 with 6 lenses + converter that cover the range from 14mm to 480mm.

Before Audio and Marriage/Kids(listed in order of discovery):
Guitar(age 12), Chess(age 16), Table Tennis(age 18), Photography(age 18), Cycling((age 22)and Weight Lifting(age 24...wanted to impress a girl that worked at the local Gym).

After: Chess, Table Tennis. About to jump back into the Camera/thing again along with lifting. Need Knee surgery(again)to force me to aquire a new bike with Campy Record 10 carbon(which I had).I still think about playing guitar everyday.

Really interesting. 
Audio gear has taken over the #1 spot from golf and sports cars, Vintage Porsche 911's to be precise. I just got tired of working on them. I still play golf twice a week but not as pationate about it since audio took over. 

Also spend alot of time with my 3 year old grand daughter. That is truly the most important and fun thing I do. 

I am allways looking to try new things though. 

Not much time for anything else.