I live in the San Francisco Bay Area, and Monterey and its surrounding area makes for an easy day trip. Some of my recommended things to do:
--Monterey Bay Aquarium
--Walk around Cannery Row and its shops
--Walk around downtown Carmel (only 5 minutes south of Monterey on Hwy 1)
--Visit the Earthbound Farms Cafe on Carmel Valley Ranch Road, just south of Monterey on Hwy 1).
--Drive the 17 Mile Drive in Pebble Beach. Warning: $9 fee to drive into this beautiful gated community)
--Visit downtown Carmel Valley: more rustic and accessible than Carmel and great food
--Maritime Museum of Monterey