What framework are you using for your PHP work? If you aren't using a framework (because your work doesn't need one), then switching languages probably isn't going to change much, but if you are, there are several good, fun PHP frameworks out there. The best PHP framework I've used is Symfony (http://www.symfony-project.org/), which is actively developed, fun to work with, and really powerful.
I've worked in CodeIgniter, but these days I find myself using the Zend Framework (http://framework.zend.com/). They're actively developing it, and it has so much built-in functionality that I've been able to get stuff done much faster than before.
