This post was just published on the AppFabric Team Blog.
In this tutorial, Alan Smith (MVP) uses the Windows Azure AppFabric June CTP to create a basic custom external service to call the BingMaps Geocode service. This is a great starting point on how to write a basic custom external service fully integrated with the Windows Azure AppFabric designer June CTP. Look for the webcast version coming soon on AppFabric.tv and follow up posts to add more capabilities to this custom external service, such as rich domain-specific monitoring metrics and tracing integration.
Thanks to Alan for his active contribution to the AppFabric community!