This is the van that drove around taking the photos for Street View. Click on the image to zoom in:
Boing Boing has more information on one of the vehicles that was used to create Street View. People speculate that the van in the image was used to capture the San Francisco Bay Area, which has very detailed photos, and that the vehicle in the Boing Boing article was used for the other cities, which don't have as detailed pictures.
(Currently Street Views works for the San Francisco area, Las Vegas, Denver, New York, and Miami.)