Cocoon P2P is an open source peer-to-peer library for Flex/AIR and mobile devices that makes peer discovery, messaging and object replication via the RTMFP protocol easy and straightforward. It was created with simplicity in mind and does most of the work (connection and group creation, message handling etc.) automatically for you.
By default, it uses LAN only RTMFP connections (no server involved) which allows to easily connect multiple devices on your LAN/WLAN but it can also be used with Adobe's Cirrus service. Future version will support Flash Media Server as well.
More information, sample and source is available at the project's home page.
Cocoon P2P was created by Peter Elst and is maintained by Peter and myself. For updates you may want to follow Cocoon P2P on Twitter