http://www.zend.com/phorum/read.php?num=6&id=668&loc=0&thread=668

[quote]
First, object representation in different contexts. Currently, if we write: 

echo $object; 

PHP produce not much of information about instance: 'object'. I have read many articles about new PHP5 features where I found note that we will be able to use an object in a 'foreach' instruction, like an array, if this object implement container interface. This is great - I think about an another usage of this concept - using an object as a string. For example, if class provide an specific method (magic function?): 

class TSerializable { 
function __value() { 
return $this->toXML(); 
} 
} 

we will be able to use it like a simple value - an object will be automatically converted (with a method defined by the user) to a 'primitive' representation: 

echo '<tag>'.$object.'</tag>'; 

or 

<?=$object; ?> 

This will be very useful - e.g. in serialization, debugging and PHP-based templates because we will be able to use general syntax to streaming simple and complex data. 
[/quote]