It's become THE thing to do lately. You can't go anywhere in my town without seeing people playing. The largest hotspot is on the campus of my local university where you can be touching five PokeStops by sitting anywhere in this large, open field next to one of the buildings. Students and non-students, kids and adults are there literally 24/7 with lure modules up. I've been going up there with friends every night and there's always at least 100-200 people. We all bring food, coolers, lawn chairs and blankets, music, etc. The university even has some people come out during the middle of the day (since its always 100+ here and that doesn't deter people) giving out free water and snacks every so often.
Our city is holding a Poke Walk down the largest, main road downtown (that has tons of PokeStops up and down it) on Saturday as a huge event and nearly 1000 people have already RSVPed on Facebook.
I've met so many new people and made so many new friends since this game released. I've spent more time outside than inside and it actually feels weird/boring sitting here behind a computer screen.