For one day, drive down Highway 1, Stop at Ft. Funston to watch the hang gliders fly 40 ft. overhead. Devils Slide, Santa Cruz, Monterey (for the Aquarium and Monarch butterflies), Carmel by-the-sea (for the shopping) and home. A bit tight for one day, but doable. You can separate Ft. Funston, Highway 1 and Santa Cruz from the rest for a two day trip. Overnight in Monterey for this.

For a second day check out the Oceanic Society for a whale watching expedition to the Farallon Islands. I think they are still showing my slide show on the way out. It is an all day trip, but very cool.