Our original belief that a chapter on supporting online play with GameKit would be long turned out to be accurate. The first draft of the online play chapter just knocked the last Core Data chapter off of its pedestal. Clocking in at 56 pages, this chapter goes through the process of creating re-usable objects to listen for network connections and to exchange information with other devices using streams. We also show you how to use Bonjour to find and connect to peers on your local network.
It's been a bear to write, but I think it's good addition to the book. I could be wrong, but I think this will be the most comprehensive step-by-step guide to adding online play to a GameKit application that's available and, frankly, most of the hard work was in writing the two reusable classes that you'll be able to just copy into other projects and use.