What is a niche hobby of yours that you are fascinated by and would like to share with others?
I'll start. I have recently gotten into 3D printing, and, while incredibly frustrating sometimes, there's nothing more rewarding than getting a perfect print.
I'm a big fan of amateur radio, specifically portable operation, and Parks on the Air.
I'll take my radio out to a remote location, throw an antenna up into some trees, and talk to people all over the US.
Currently I need mains power, but I'm looking to buy a battery soon, and I already have some solar panels gifted from a club member.
I live in Michigan, and last time I was out, my most distant contacts were in Dallas, Texas, around 1100 miles away, while I was sitting at a picnic table at my local state park campground.
I got my Amateur Extra and my girlfriend went and got hers and she bought a KX2. I guess I shouldn't be too surprised since she likes hiking and camping so much. She's been working on her tent and radio setup and bought a super light antenna mast she can put up in a few minutes. We need to get some time, and things need to cool off a bit, but we'll have some fun for sure. I have enjoyed listening to people making contacts on the ISS and satellites overhead via amsat; it blows my mind these little things are bouncing signals around: https://spacecomms.wordpress.com/2017/11/21/just-launched-ao-91-will-be-a-great-bird/
Slow scan TV and digital stuff like FT-8 bouncing literally around the world are fun to play with at home too.