Technorati requires a valid API key for usage. To get your own API Key you first need to create a new Technorati account, then visit the API Key section.
API Key limits
You can make up to 500 Technorati API calls per day, at no charge. Other usage limitations may apply, depending on the current Technorati API license.
Once you have a valid API key, you're ready to start using
Zend_Service_Technorati.