Maps+Motion is a great way to visualise the growth of Dutch cities and Manhattan in New York with Google Maps.
Essentially the application allows you to view side-by-side the modern maps of cities with maps of how the cities looked at different times in history. The screenshot above, for example, shows a map of 1450 Amsterdam with a modern map of the city.
The application currently allows you to view the historical growth of Den Haag, Harrlingen, Amsterdam, Leiden, Rotterdam and Zuiderzee in the Netherlands and Manhattan in the USA.