Sameer has posted an introduction to a topic he'll be writing up a series on - refactoring for PHP developers:
In the coming year I'll be starting a series on Refactoring. Refactoring is one of those programming ideas besides Design Patterns and Unit Testing which has made an order of magnitude improvement in my productivity. Although refactoring may not be a 'Silver Bullet' for your programming woes, it is a good tool to add to your mental toolbox.
This initial post defines refactoring, looks at how its different than code optimization and lays out some of his plans for what he'll cover in the series.