Example code from "The Last Authentication System You Will Ever Write", done
at php|tek 2011.

Installation
============

1)  Extract files to a directory visible to your webserver.

2)  Register your domain with http://developer.twitter.com.

3)  Set your callback to http://[path-to-your-project]/callback.php

4)  Note the consumer key and secret from twitter.com.  Add them to
    their respective values in your config.php file.

5)  Create a folder called "library" at the root of your project

6)  Download Zend Framework (http://framework.zend.com) and extract the
    library folder to your library folder.

7)  Replace "callbackUrl" in config.php with the path to your project
    callback.php file.

8)  Access your project URL and go!