WsdlToPhp
Generate PHP classes based on a WSDL
...The SOAP client is then abstracted and you only deal with objects representing the WSDL.
It uses eZ Components, ezcPhpGenerator, in order to generate php files.
Test this library here : http://www.wsdltophp.com
Read the online PHPDoc here : http://phpdoc.wsdltophp.com/