aws_s3.rb

module Starfish
  module AwsS3
    
    # S3Archive initializes and provides archival-oriented access to an S3 bucket.
    class S3Archive
    
      def initialize
        config = YAML.load_file("#{File.expand_path('~')}/.ec2/aws-secret.yml")
        AWS::S3::Base.establish_connection!(
                  :access_key_id     => config['aws']['access_key'], 
                  :secret_access_key => config['aws']['secret_access_key']
                )
      end
      
      def bucket(name, create=false)
        AWS::S3::Bucket.find(name) || AWS::S3::Bucket.create(name)
      end
      
      # Accepts a string or IO object. Compresses string data with zlib deflate.
      # Zlib::GzipReader generates an IO object compatible with this method.
      def put(bucket_name, key, data, opts={})
        options = {:content_type => 'binary/octet-stream'}.merge(opts)
        data = StringIO.new(Zlib::Deflate::deflate(data)) if data.is_a?(String)
        AWS::S3::S3Object.store(key, data, bucket_name, options)
      end

      # Accepts a string or IO object. Expands string data with zlib inflate.
      # Zlib::GzipWriter generates an IO object compatible with this method.
      def get(bucket_name, key, io=nil, &block)
        if io.respond_to?(:write)
          AWS::S3::S3Object.stream(key, bucket_name) do |chunk|
            io.write chunk
          end
        elsif block
          AWS::S3::S3Object.stream(key, bucket_name, {}, &block)
        else
          Zlib::Inflate::inflate(AWS::S3::S3Object.value(key, bucket_name))
        end
      end
    end
  end
end

aws_secret.yml

# Sign up for AWS and get your keys: http://aws.amazon.com/
# Keep your secrets out of the project repo. :)
aws:
  access_key: XXXXXXXXXXXXXXX
  secret_access_key: XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
  account: XXXXXXXXXXXX

sqs_queue.rb

module Starfish
  module Pipeline
    
    # SqsQueue initializes and provides basic access to an AWS SQS queue.
    class SqsQueue
      attr_reader :queue, :name, :sqs
    
      def initialize(name)
        config = YAML.load_file("#{File.expand_path('~')}/.ec2/aws-secret.yml")
        @sqs = RightAws::SqsGen2.new(
              config['aws']['access_key'], 
              config['aws']['secret_access_key'],
              {:logger => Rails.logger})      
    
        @name = name
        @queue = @sqs.queue(@name, true, "1")
      end
    
      # This method enqueues a message, assumed to be a Ruby hash object,
      # which is serialized to JSON.
      def send(message)
        @queue.send_message(JSON[message])
      end
    
      # This method both receives and deletes the message, assumed to be a JSON
      # object, and converts to a Ruby hash object.
      def pop
        if message = @queue.pop
          JSON[message.to_s]
        end
      end

      # This method peeks at a message and triggers the visibility timeout,
      # but doesn't remove/delete the message.
      def receive
        if message = @queue.receive
          JSON[message.to_s]
        end
      end
    
    end
  end
end

In S3Archive#initialize, there's no need to make the config variable and instance variable as you are not referencing it outside of that method. You might as well just make it a local variable (which I've already done).

• In SqsQueue#initialize, you mixed interpolation & concatenation again. I fixed it.
• Again, config can just be a local variable. It doesn't need to be an instance variable (which saves memory--the garbage collector can reclaim it after initialize runs).
• Is it really necessary to expose queue, name and sqs to consumers of SqsQueue? I thought the point was that SqsQueue wraps SQS. I'd prefer to not expose those so that it forces all consumers to use the interface you've provided.
• I'd be careful naming your method send since that's a method defined on all ruby objects with the specific meaning of calling the named method. You've overridden it here to mean something else, which could be a source of bugs later on. Maybe enqueue would be a better name?