The image above shows square mile diagrams of cyclable routes in the area around the Stationsplein in Amsterdam, the Hague, Rotterdam and Utrecht. I made the maps with OSMnx, a Python package created by Geoff Boeing, a PhD candidate in urban planning at UC Berkeley (via).
Square mile diagrams are a nice gimmick (with practical uses), but they’re just the tip of the iceberg of what OSMnx can do. You can use it to download administrative boundaries (e.g. the outline of Amsterdam) as well as street networks from Open Street Map. And you can analyse these networks, for example: assess their density, find out which streets are connections between separate clusters in the network, or show which parts of the city have long or short blocks (I haven’t tried doing network measure calculations yet).
Boeing boasts that his package not only offers functionality that wasn’t (easily) available yet, but also that many tasks can be performed with a single line of code. From what I’ve seen so far, it’s true: the package is amazingly easy to use. All in all, I think this is a great tool.