Man, I hate to bring folks down, but take a look at this - the USGS has rephotographed George Lawrence's famous photo of the ruins of San Fran taken just a few weeks after the famously apocolyptic 1906 earthquake. Super high resolution and completely zoomable, it is really a pretty amazing piece of work.
The picture, zoomed out, looks thusly:
Pretty awesome stuff, and kind of hard to comprehend the complete destruction. Anyway, you can find the image and info regarding how it was updated and digitized here.