Having a good debugger and error reporting can mean the difference between spending an hour hunting down the line of code causing bug and killing it quickly. For PHP, xdebug is my preferred debugger (are there others?),.  Thanks to this link on debuggable.com, I was able to find a precompiled binary for OS X. Setting up Xdebug on Mac OS X (or Win32 / Linux) » Debuggable Ltd

Anyway, one of the biggest obstacles when getting started with Xdebug was that I had a hard time finding good instructions on how to set it up on Mac OS X (I finally got rid of windows, yeah !). The only good resource I found was stored in Googles cache (wasn\'t live anymore) and had instructions on how to manually build xdebug from source. However, I didn\'t have a lot of time back then and compiling would have involved setting up all kinds of additional tools. This was the point when I vaguely remembered that the Komodo IDE was using xdebug. So I did some more research and sure enough, the good folks over at ActivateState actually provide their Xdebug binaries as stand-alone downloads for all major platforms.