This page lists some guitar-friendly venues (etc) in the San Francisco Bay Area.
It's mostly oriented toward classical and fingerstyle, because that's my taste...
It won't be of much direct benefit to folks who live elsewhere,
but it may suggest some things to look for (or start!).
Here, thanks to Google, is a map that shows most of the locations!
The San Francisco Bay Area Acoustic Guitar Society
lists a lot of local events.
Bars, Coffeehouses, Diners, Pubs, etc.
The Good News about these places is that you can eat and drink while you listen and watch.
The Bad News is that you may have to hear other folks eating, drinking, and talking.