If you have two spare hours in San Francisco then rent a bike (somewhere in the Fisherman's Wharf area) and ride over the Golden Gate Bridge to Sausalito.
If you are lucky to have the bridge in the fog on this day, than you are really lucky !
I took this picture just before enetring the bridge.
Here is the route:
1. Ride through Aquatic Park towards Golden Gate Bridge
2. After visiting Fort Point (Free!) (4) follow signs to cross the bridge.
3. After crossing the bridge, exit via Vista Point parking lot and down Alexander Avenue into Sausalito.
4. Have a Corona beer and ride back.
5. N-joy.
6. Phone someone from Sausalito and tell her/him about your ride.