For a web service of your choice (use the APIs directory at programmableweb.com) write a script that fetches data from the service and uses it, in the context of your project.
Using 2 external web services (SOAP or REST style), write a small application that would chain them to produce a response for the user input.
In the context of your project, make the data available to other applications through a web service (SOAP or REST style).