Zend_Service_Amazon_S3 provides the following functionality:
A single point for configuring your amazon.s3 authentication credentials that can be used across the amazon.s3 namespaces.
A proxy object that is more convenient to use than an HTTP client alone, mostly removing the need to manually construct HTTP POST requests to access the REST service.
A response wrapper that parses each response body and throws an exception if an error occurred, alleviating the need to repeatedly check the success of many commands.
Additional convenience methods for some of the more common operations.