1. A method for enabling a user to view data from an external data source in a visual map, wherein the external data source has a web service interface, the method comprising: providing, on a computer, a visual mapping interface that enables a user to add to a visual map one or more map parts associated with software code capable of making a call to a web service (a “web service map part”), wherein a user is able to add a web service map part as a topic or a subtopic to a visual map; building a web service request for the external data source in response to a user initiating the adding of a web service map part to a visual map; sending the web service request to the web service associated with the external data source; receiving data from the web service in response to the web service request; transforming the data into a format that can be used to generate visual map content; displaying the web service map part in the visual map; and displaying the data received from the web service in response to the web service request either within the web service map part or as subtopics to the web service map part.