Court Ewing has put together a new post looking at using one of the more powerful (yet underused) features of the recent PHP releases - namespaces - to organize your code.
Prefixes serve their primary purpose well: when used correctly, they will ensure that your class names do not have naming conflicts. Unfortunately, they are long and pedantic, and provide no additional benefits. [...] Namespaces provide other benefits than shorter class names, though.
He illustrates with a well-structured example that makes it clear as to what resources are being used and how they're split out. His snippet defines the structure of the rest of the script without even a line of code in the class. He also briefly mentions the PHP 5.3 adoption levels and notes that several larger projects will be 5.3-only soon and will start to force the hand of developers and hosting companies.