Integration with webservices

Hello everyone. I apologize in advance if this is the wrong forum for the question.

I'm trying to understand how to integrate Drupal with 3rd party web services. In particular, I'm playing with OpenID integration. I want to display user's "full name" in the header. That involves invoking a function in the OpenID module from within the header template. Is this the proper way to do it? The reason I'm asking is taht I'm expecting a few more web services calls. Hardcoding this stuff within the template seems ugly and fragile. Is there a better approach?