A new version of XML-RPC for PHP has been released, incorporating new helper functions in addition to bug fixes.

Version 1.0b8 adds the following features:

• xmlrpc_debugmsg() method allows sending of debug info in comments in the return payload from a server
• xmlrpc_encode() and xmlrpc_decode() translate between xmlrpcval objects and PHP language arrays

Bug fixes include the correct sending of "Content-length" header and whitespace handling issues. A full changelog is available online, as is documentation.

(Disclosure: I'm the author of this software!)