In my continuing effort to keep abreast of urban history-themed apps for mobile devices, today I’m featuring a new IPhone app developed by a team from the Edinburgh College of Art and University of Edinburgh, Walking Through Time. It syncs historical maps of Edinburgh with the current, GPS-enabled map on your IPhone so you can navigate both geographically and chronologically as you stroll around Edinburgh. You can set the application to follow maps from a range of different time periods, 19th and 20th century. You can also toggle back and forth between old and new, or customize the transparency level to view both maps at the same time. A set of walking tours gives the application some structure if you don’t want to wander aimlessly.Chris Speed, one of the developers, was quoted in the Edinburgh Journal: "The great fun is giving it to someone and then taking them to where a street doesn’t exist and say ‘walk’, but they can’t because there’s a new building in the way.” Here’s a brief video explaining the Walking Through Time concept:[youtube=http://www.youtube.com/watch?v=bJwYv-6wgf8]When the project launched, Walking Through Time featured historical maps of London as well, but only for a brief promotional period. The team is negotiating a long-term rights contract to include the London maps permanently, and hopes eventually to branch out to other parts of the UK.Comments from users, posted on ITunes, have been mixed. Sounds like there were some glitches out of the gate (which may now be fixed), and Londoners want their maps back. But it’s clear that we are going to see more and more of these GPS historical apps in the next few years, and with experimentation and practice they will get better and better.Which reminds me of this great little animation that Plate of Peas Productions developed in 2007 for the Old State House, the museum I used to run in Boston. It shows nearly 300 years of change, both to the Old State House itself and to the neighborhood around it, sped up at a rate of roughly 15 years per second. You can see it here, as part of a longer History Channel piece about Old State House preservation, 1:10 into the video:[youtube=http://www.youtube.com/watch?v=DalYthWk6FU]I’m wondering if all this technology is heading to a place where the historical timeline is visible, the way it is in the Old State House animation, not just for a few landmark buildings but on every street corner throughout the city. That means many layers of history, all open to us simultaneously, so that we toggle back and forth between the present and many different pasts seamlessly. And then what does that do to our everyday experience of the city? And what does it do to the city museum?