Walk through time online
WhatWasThere: A crowd-sourced interactive photographic map of the world that includes presentday and historical photos, on location. Very easy to use – see the old photos of Hobart.
Old S. F.: An interactive map of more than 16,000 geotagged photos of San Francisco from 1850 to 2000, sourced from the San Francisco Public Library’s Historical Photograph Collection. Fascinating. oldsf. org
Snapr: A social website and mobile app that lets users share geotagged photos from around the world. Search by location, tag or user. http:// sna. pr