https://github.com/tsloughter/opa_pubnub_plugin
http://blog.erlware.org/2011/11/23/opa-plugin-development-with-a-pubnub-example/
You must have a pubnub account to use the API. http://www.pubnub.com/account
PubNub is a Massively Scalable Real-time Service for Web and Mobile Games. This is a cloud-based service for broadcasting Real-time bidirectional messages to web, mobile, TV, tablet and GPS clients.