This little implementation of the OPML blogging system written in PHP now supports the XML-RPC based MetaWeblog API (another creation of Dave Winer), meaning I can now post to my blog from a variety of devices and platforms. 
It uses the Incutio XML-RPC Library for PHP, an old library put together by Simon Willison.
I wish there were a library of test cases for MetaWeblog API based on the real-world behaviour of weblog posting clients. It's difficult to fully implement MetaWeblog unless you know exactly what the client is going to give you.
Perhaps what we should do is have a few sample blog posts which people would try to enter using their MetaWeblog (or Blogger or Movable Type or Atom Publishing Protocol - such being the nature of standards that you have four of them) clients, then we might be able to have some test cases.
As for the OPML blogging engine in PHP? I will release it quite soon - I just want to clean up the code and make it a bit nicer to use.
