San Francisco has some pretty fun nightlife. Overall though you will find stuff closes earler in California than it does back in England. I'd suggest going up to Tahoe area. You're in the Mountains and it's BEAUTIFUL up there. You can also head over to Reno to do a spot of gambeling and see the desert like lands of Nevada....

Don't listen to those who live South of San Louis Obisbo.... They're just jealous they don't live in Northern California..... (And yes SLO is pretty far south... but I'd say it's cool enough to be considered the north... ;-) )