Located next to the Golden Gate Fields horse racetrack is a hidden gem called the Albany Bulb... a 'trash-heap' with scattered artwork all over.
This is where you can find it:
View Larger Map
And here are some pictures of what you can find there, taken with my Olympus E-520 with the kit 14-42mm f/3.5-5.6 lens :)
Make Love, Not War:
A Window to the City (SF):
You can find more of these pics, and their full size images at Mattaphore.Deviantart.com