Amazon VPC

かなり使いやすくなった予感
http://aws.amazon.com/about-aws/whats-new/2011/03/15/Announcing-VPC-Internet-Gateway/

With Amazon VPC, you can define a virtual network topology that closely resembles a traditional network that you might operate in your own datacenter. You have complete control over your virtual networking environment, including selection of your own IP address range, creation of subnets, and configuration of route tables and network gateways. You can easily customize the network configuration for your Amazon VPC. For example, you can create a public-facing subnet for your webservers that have access to the Internet, and place your backend systems such as databases or application servers in a private-facing subnet with no Internet access.