First, click here or click on the photo shown below. This will take you to Zooomr. Then place your mouse over the photo to find the portals. They appear as rectangular outlines overlaid on the photo. It will take a few seconds for the portal to appear as an image within an image. Clicking on the portal will give you a more detailed view. Do this again on the next photo. Eventually you will get to close-up detail on several San Francisco landmarks such as Coit Tower, Palace of Fine Arts, and Alcatraz.
It appears that Zooomr portals does not work with Internet Explorer. It works best with Firefox.