registerS3ProtocolStreamWrapper.php

<?php
define('AWS_KEY','YOUR_AWS_KEY_HERE');
define('AWS_SECRET','YOUR_AWS_SECRET_HERE');

require_once('AWSSDKforPHP/sdk.class.php');
require_once('AWSSDKforPHP/extensions/s3streamwrapper.class.php');

$s3 = new AmazonS3(array(
    'key' => AWS_KEY,
    'secret' => AWS_SECRET,
    'default_cache_config' => '',
    'certificate_authority' => true
));

S3StreamWrapper::register($s3);
>

usageExampleWithoutStreamWrapper.php

//rename the object 'foo.txt' to 'bar.txt' in bucket 'myBucket':
//there is no 'rename' method in the API, so we first have to copy the object
//to the new location, and then delete the old one:
$response = $s3->copy_object(
    array(
        'bucket'   => 'myBucket',
        'filename' => 'foo.txt'
    ),
    array(
        'bucket'   => 'myBucket',
        'filename' => 'bar.txt'
    )
);
if ($response->isOK()){
    $response = $s3->delete_object('myBucket', 'foo.txt');
    if (!$response->isOK()){
        //handle error...
    }
}

//read contents of object 'foo/bar.txt' in bucket 'myBucket':
$data = $s3->get_object(
    'myBucket',
    'foo/bar.txt'
))->body;

//store data in object 'foo/bar.txt' in bucket 'myBucket':
$response = $s3->create_object(
    'myBucket',
    'foo/bar.txt',
    array(
        'body' => 'data...'
    )
);

usageExampleWithStreamWrapper.php

//rename the object 'foo.txt' to 'bar.txt' in bucket 'myBucket':
rename('s3://myBucket/foo.txt', 's3://myBucket/bar.txt');

//delete the object 'bar.txt' from bucket 'myBucket':
unlink('s3://myBucket/bar.txt');

//create a new bucket 'mySecondBucket':
mkdir('s3://mySecondBucket');

//read contents of object 'foo/bar.txt' in bucket 'myBucket':
$data = file_get_contents('s3://myBucket/foo/bar.txt');

//store data in object 'foo/bar.txt' in bucket 'myBucket':
file_put_contents('s3://myBucket/foo/bar.txt', 'data...');