UPDATE: Turns out this has already been done! Oh well, I still had fun with it.
Last night I followed a link from Reddit to The Berlin Wall: 20 Years Later on the New York Times site. It was an interesting feature, but I thought that the use of Flash to display the before and after photos was a little bit gratuitous, especially considering that they could make the content accessible to a wider range of user agents (mobile browsers and Google image search come to mind) by using CSS and Javascript.
