Even though I largely work with symfony and CakePHP, I tend to follow the Zend Framework coding practices. Generally, any private and protected methods and members are first. I usually list them in the order they’re used, but that’s not a requirement in PHP. In my classes, the __construct function is the first public function, followed by the other public functions. While Zend may not do this (I’m not sure, actually) I put static public methods at the very end. I couldn’t tell you how to organize data members beyond there since I virtually never, if at all, use any public members.
If you’re looking for clean code, use self-documenting names. Don’t be afraid to use longer names if they’re more descriptive. I would rather a method be named getUserInformationFromDatabase than it be called something like userInformation, etc. If you don’t already, use phpDocumentor comments for all of your files, classes, data members, and methods.