I agree with Amos- there's an awful lot to see and do in the San Diego area. The San Diego zoo is one of them, although I actually prefer the San Diego Wild Animal Park some miles away. It's an open 'zoo' where animals mix and mingle with various other species- the viewing 'platform' is a train that travels the perimeter.

On San Francisco's waterfront there are also many mustn't-miss points.

If you like driving the 101 (I, for one, do), go on up north toward the Oregon border and spend some time in the Redwoods. Wonderfully timeless atmosphere.

I too would cut the driving time to a minimum unless you resonate to the vast scope of California's length, its changing terrain and resulting different climates and vegetation.