Lawrence Byrd, Director of Unified Communications Architecture at Avaya kicked off the keynote schedule of the Communications Developer conference on Tuesday with a presentation entitled Unified Communications in a Web 2.0 World.   The gist of the speech was that developers will play a critical role in the future of communications, and in fact the developer community is the engine that runs the IP communications world.   Byrd threw about several definitions of "2.0," including one from Tim O'Reilly that defines the Web 2.0 phenomenon as "...networked apps that explicitly leverage network effects."   Byrd also used this definition from Harvard Business School's Andrew McAfee, "Enterprise 2.0 is the use of emergent social software platforms within companies and between companies and their partners and customers."   In any event the developer community should recognize this as an opportunity; an expanded playground to create ways of connecting these elements to deliver added value for their end customers.   "We've spent the last 20 years trying to connect the phone to the Web," said Byrd. "Connect the Web to the store. That is the definition of unified communications, connecting both the old and the new."   And as we move ahead we need to be sure that legacy applications and modern cutting edge applications work well together. That is how we add value. It has to work together.