Amazon Web Services introduced a peering capability for its Virtual Provide Cloud (VPC) service, which lets users create a logically-isolated section of the AWS Cloud.
The enhancement provides the ability to create a VPC peering connection between VPCs in the same AWS Region. For instance, Amazon EC2 instances could already be connected to a Virtual Private Cloud. Now, EC2 instances in the peered VPCs can communicate with each other across the peering connection using their private IP addresses, as if they were within the same network. Up to 50 VPCs in the same region can be peered with each other, and they do not have to be registered to the same AWS account.
More details are online.
http://aws.typepad.com/aws/2014/03/new-vpc-peering-for-the-amazon-virtual-private-cloud.html