If you have a library of code you want to convert to PHP 5.3 namespaces and it follows the Zend class naming standard, this tool will do the grunt work for you. Clone the repo using git or just grab the archive and start playing with it.
The fun version
RALPH! That’s how these conversations usually start. I can feel Ralph cringe over IM every time I do that too. (And I can see Matthew smiling reading this because it used to be MATTHEW!) Ralph Schindler is one of 2 full-time Zend employees whose job it is to work on the Zend Framework. (Yeah, awesome job if you can get it!) Ralph works on a lost of stuff but my favorite is Zend_Tool. Every time Ralph releases a new version of Zend_Tool, he and I end up having an extended debugging session making sure that my zf twitter client still works.