Then I read this: http://paltman.com/2007/05/29/amazon-s3-and-filename-magic but I don't really understand the advantage of storing an object on S3 whose key is the hash and which points to the GUID. One thing I don't want to do is store the GUID as the S3 key (to prevent massive scraping of all the assets).
How are you all dealing with this? Is anyone using a MD5 or SHA-1 digest as the key? A salted hash of the GUID as the key?