To use the WCF, you must first have a file known as a generated client class. This class for use with a PCL must be created using the Silverlight Svsvcutil binary that comes as part of the Silverlight SDK. A similar named binary (svcutil) comes as part of the Windows SDK. Do not use this binary because the client class produced cannot be used in the PCL. The client class can only be generated on a Windows machine (or on a virtualized Windows machine).

For this, I've chosen to use Microsoft's VirtualEarth service. To use this, you will also need to generate a temporary key. This key is similar to a Google Maps key or the OpenWeatherMap API key, which is needed when communicating with the service to authenticate who you are. The key is free. When you create the key, ensure that the key is a trial key and the type is Other Public Mobile App. Copy the generated key and store it in the public readonly...