The hobby? Contributing to OpenStreetMap. I found an app called Street Complete that makes it exceptionally easy, basically it just asks you questions about features along your walking route. Thanks to doing this, I've discovered several hidden features of the neighborhood like small public gardens full of herbs, public library boxes, and more.

Doing it also feels constructive, because I know I'm helping build up a resource to challenge Google's near-monopoly. It's very satisfying to clear all the dots from the map, and I find myself looking forward to my walks and planning out which streets I'll walk next.

Happy helping!