The AWS CLI, in a Docker image
Handy for CoreOS, where running a Docker image is easy, but installing the AWS CLI is hard. For instance, you could use it to download stuff from an S3 bucket that requires authentication.
This is set up with an automated build at Docker Hub, and the entrypoint is the aws executable, so you can use it like this:
docker run --rm paperg/aws aws s3 ls
Of course you will have to configure credentials somehow; if you are running it from at EC2 instance with an associated IAM profile, it will use those automatically.