Just published an extension on the Yii framework site for interacting with Amazon S3. It's very nerve wreaking to share an Extension for some reason, so I've just never posted one before.
Pretty basic but quite handy if you use their services and need to push content to them. Hopefully this one will be useful!
Forum for questions/comments/concerns is here: http://www.yiiframework.com/forum/index.php?/topic/14265-extension-es3/
The extension is a simple Yii wrapper for the extremely effective S3 class created by Donovan Schönknecht which can be found here: http://undesigned.org.za/2007/10/22/amazon-s3-php-class