Rent a bike at Fishermans Wharf. You can ride the bike across the Golden Gate Bridge to Sausalito. You can then take the ferry back to San Francisco (purchase the ferry ticket when you rent the bike). There are several places to rent bikes at Fishermans Wharf. The ride across the bridge and into Sausalito is an easy ride. It is a fun way to see the city and the bridge. The ferry ride also gives you a great view of the bay.