The chat room is the perfect tool for organizing the team communication. It completely change the way you interact with your teammates. Asynchronous communication is powerful and should be done the right way (not emails for saying we are having lunch!!). We use HipChat too (and Trello). We were so convinced that working with the right tools and the right workflow was indispensable that we wrote a book showcasing the needs we had as a team and the tools we used to fulfill these needs http://leanpub.com/startupflow.