The Developer Tutorials blog has a quick example of how to use the array_walk function to maneuver through the array of your choosing and applying a callback method to each of its elements.

It’s a common sight: taking an array and running (well, walking) its elements through a particular function. Luckily, PHP provides a simple yet powerful function to overcome this: array_walk().

They include an example, giving a sample "some_function" the array_walk method uses when it's called, replacing a foreach (or other type of loop). Plus you can specify an object with the callback to run it against a method inside a class too.

Jacques Marneweck points out a tutorial he came across showing how to perform an installation of the PEAR library system on a shared host.

This is quite useful when you are forced into using a clueless shared host who only have the bare PEAR installation on their servers, and have not ever considered installing DB, Mail, Net_SMTP, etc. which lots of people use instead of reinventing the wheel with each project.

The steps of the tutorial are pretty simple and they include two different ways - installing it to your docroot directory if the web host already has the pear binary set up or using ftp/ftps/sftp to upload and install the needed files.