In a new post to the Zend Developer Zone today the NP-Gravatar libraries are introduced as a way to hook your application into the Gravatar web service.

Gravatar is a famous web-service for providing globally-unique avatars. Gravatar, like many other web services, has its own APIs, which are based on simple HTTP GET requests. [...] By studying and analyzing those APIs, I come up with an idea to create a Zend Framework implementation of all those Gravatar services. That resulted in NP-Gravatar package, which will be presented in this post.

The project gives you two service classes and one view helper to make the integration with the frontend simpler. He explains each library and gives a code sample of them in action - grabbing profile information, an interface to the XML-RPC service they offer and the view helper to call a simple "gravatar()" method inside of an IMG tag.