Wenbert Del Rosario has a recent post to his blog today about using custom plugins in a Zend Framework application.

A few days ago, I managed to setup a project using the new command line tools. My project now had models, views and all the controllers that I needed. But then came the time when I had to setup my own custom plugins. [...] To register your own custom plugin in the new Zend Framework 1.8 release, go to you application.ini file found in the configs directory and add this [code to register the plugin on the front controller instance].

He includes an example of the settings needed for the application.ini, the location to put the plugin file in and a simple example of how the plugin would be coded.