Not folkie, but there's a couple of great bands playing the Black Diamond Brewery in Walnut Creek on Saturday the 8th. The food's not bad and the beer is great.

9pm - White Trash Compactor (acoustic bluegrass with a big sense of humor)
10pm 'til late - Mary Carves the Chicken (electrified bluesy-country-rock 'n' roll or whatever they happen to be playing that night)