Want to get away from the tourists, but not willing to commit to an all day hike? Try the Ocean View > Lost > Fossil Creek > Main loop. ~2 hours, great sights, few people Read more.
Looking to get away from the crowds on foot? Try a 4.5 mile loop hike on the Ben Johnson and Dipsea Trails. Follow the link for trail maps and tips. Read more.
Best spot to rent bikes in SF. Cheap ($24 for the day), very friendly owner, and you can drop off at Pier 39 or Ferry Building after ferrying back from Sausalito. Check out the link for a great route Read more.