Amazon S3 Bucket Policy: allow public read of any file in bucket. Note: replace 'bucket_name_here'. Source: http://stackoverflow.com/a/4709391

gistfile1.txt

{
	"Version": "2008-10-17",
	"Statement": [
		{
			"Sid": "AllowPublicRead",
			"Effect": "Allow",
			"Principal": {
				"AWS": "*"
			},
			"Action": "s3:GetObject",
			"Resource": "arn:aws:s3:::bucket_name_here/*"
		}
	]
}