I'd like to tell you about the "Categorically Not!" project that the excellent science writer KC Cole started in Los Angeles in January. Every month there's a loose theme chosen (examples so far being "holes", "strings", "fluid dynamics", "uncertainty") and people present little talks or discussions on the theme. KC draws from scientists, artists, musicians, writers, actors, poets, dancers, playwrights, etc. The variety of people you can get in LA is of course huge, and so there's plenty of local talent, but sometimes speakers from further afield too. (Note some of the resonance with Cafe Scientifique, mentioned by Mark in another post.)
Who are the people who show up to take part? Quite a cross-section from the community of the general public from Santa Monica, Venice, and West LA, but also elsewhere around the city and beyond. (There are also academics in the audience from USC, UCLA, Caltech and other ...