Sustainable hobbies?

This is intended to be along the lines of the previous threads about things we are doing differently now to be more sustainable. Many of those suggestions are practical (e.g. walk or bike instead of drive, start a vegetable garden, etc.) which are welcome and make good sense. I wonder if anybody has taken up any hobbies which are intended to be fun and ultimately sustainable alternatives to the old "flip on the television and watch the same old re-runs" which too many of us do (or did) for too long.

So here's one of mine: for the past few years I've been singing with a group of friends. We meet once a week to rehearse for a couple of hours, have a great time, and sing (occasionally) for a church or community event but much of our effort is just for the intrinsic reward of getting together for time well spent, doing something constructive and intellectually-stimulating, and going easy on the environment in the process.

Anybody else finding ways to embark on "sustainable" hobbies?