@swordjaw Of course, the easiest thing to do would be to just organize one myself and advertise it until people show up, but I'm inherently wary of not being able to curate who's showing up in the first place.
But, an artist I know around here used to do that -- advertise that she'd be working at a local cafe on her accounts every week. I went once when I still lived in the area, and it was nice!