I should have mentioned this earlier, but if there's any way that you can get there, one of my favorite things near San Fran is Muir Woods - http://www.nps.gov/muwo/index.htm. If you have a car, it's a fairly short drive from the Golden Gate Bridge, but it's like stepping back in time. Sounds from the "real world" don't seem to penetrate into that redwood forest, and the trees are absolutely awe-inspiring. Of course, there's PLENTY to do in San Francisco if you aren't renting a car. Be sure to allow lots of time to laugh at the sea lions at Pier 39. They're such characters!

I love northern California (really should go back now that I think about it), and as great as San Francisco is, there's so much around it that's even better. The Monterey area is incredible. The Montrerey Bay Aquarium - http://www.montereybayaquarium.org/ - is one of my favorite places that I've visited on any trip, and the 17-Mile Drive through the Pebble Beach golf course - http://www.pebblebeach.com/activitie.../17-mile-drive - is truly beautiful. We did it twice while we were there - once on a fairly calm day and again before we left when it was stormy. I couldn't resist seeing it again when the waves were crashing in.