Do you understand what the different php.ini settings around error messages are and how to use them? Here's a description of some of the most important settings related to errors and how to use them effectively.
One long-awaited feature of CodeIgniter 2.0 is using a controller for the 404 page. Unfortunately it doesn't quite work in all situations. Here's one appraoch to fix the behavior.
How to modify the query string in a given url. Can be very useful when implementing pagination.
Trying to create an ics file using PHP? Here's one way to do it.
Looking for a simple way to share code with fellow developers on a local network? This post shows one way to do just that using PHP.
Using Xdebug on OS X without installing a 3rd party version of Apache is possible, here's how.
Storing the latitude and longitude of addresses in your database speeds up the generation of map-based mashups. Here's a solution using the Yahoo! Geocoding API.
If you've run into problems with PHP's http_build_query function, setting arg_separator.output may help.
Using a Windows hosting account where you don't have the ability to modify IIS configurations? Here's one method for setting up a canonical redirect.
Having trouble getting a redirect to work in Opera? This might help.