Converting various DB's to MySQL using PHP

Hi all -- Summary: Using PHP, need to go from ACCESS -> MySQL. (Millions of records, hundreds of tables.) I am about to embark on a project over the next week which entails (in part) developing a PHP platform that will convert an Access DB to MySQL, as well as perform all needed error-checking and appropriate field-type setup. In the future I will modify the same script to support other DB types like Postgres, MS, Oracle, etc. Rather than having PHP access these foreign DB types I will have it access a delimited text output of the DB's. Before I got started, I thought I would check in here to see if anybody knows of a similar tool that already exists.... and perhaps I can learn something from it and benchmark against it as I proceed. Also, any tips or advice would be muchly appreciated. I am sure this has been done many times over in PHP but I do not see where. Thanks!! Justin