Markus Pullmann has a new post to his blog about setting up XDebug in your PHP installation to help you narrow down those elusive issues more quickly.

Debugging locally is a nice improvement to have no debugger at all, but in many situations there is the need to debug on production server, where the application is running on the web. There are different reasons for that, but the most important one for me is, that my local environment / installation is different from the one i have on servers in data center and bugs can be related to the environment.

He walks you through the installation and server-side configuration of XDebug first then shows how to install the Komodo Remote Debugging Client to help with multi-user debugging setups. He mentions setting up the debugging on the client/IDE side, but there's no specific instructions for any particular IDE - just how it works overall.