Other than for hobby use, you could use this for text messaging in situations where you don't have cell signal or wifi. Say you're out camping and don't have a connection, assuming everyone had a LoRa radio running meshtastic, you could text each other. It also allows encryption, unlike traditional radio services like FRS/GMRS/CB/MURS or ham radio. And since it's a mesh, you can somewhat get around line of sight issues.

Yea, it's mainly for fun/experimentation. I got a $15 Heltec board and a decent antenna and could reach some nodes in SF down to San Bruno from hills in the East Bay.

But I was surprised that there's only 5-10 active nodes in the North Bay and fewer people than that - Bay Area being what it is (was), I was hoping there'd be a a little underground community.

Talk to 20 or so other nerds (and some preppers) in your city when you're driving around, or if you go up to a high point, about how well (or poorly) your Meshtastic experience is going.

At least in the Midwest, USA. It sounds like in the UK, parts of the country have had issues with overloading the mesh with current firmwares.