Matthew Weier O'Phinney has put together a guide to answer some of the questions he's been getting about combining the Zend Framework and Dojo functionality for autocompletion.
I've fielded several questions about setting up an autocompleter with Zend Framework and Dojo, and decided it was time to create a HOWTO on the subject, particularly as there are some nuances you need to pay attention to.
He shows how to set up the correct Dijits and how to create the default form element in a Zend_Form instance. He creates a data store and a QueryReadStore to hold the information. The then modified that default Zend_Form element (a ComboBox) to include the storeType and storeParams for these instances.