Martynas Jusevicius has a new post looking at method overloading in PHP5 - a workaround to make it possible at least.

Method overloading (a feature of object-oriented programing which allows having several class methods with the same name but different signatures) is not implemented in PHP, which is a drawback compared to Java. However, PHP 5 provides a way to imitate overloading by catching calls to "inaccessible methods" with magic method __call.

In his example he uses __call to route the request to the correct version of the constructor (__construct0 or __construct1) based on the number of arguments passed in