An anonymous reader writes "According to an article in Xconomy, iPhone hacker and author Jonathan Zdziarski was invited to speak at an Apple Store in Cambridge, MA last week where he talked about the history of iPhone hacking, jail-breaking, and limitations of the official SDK. From the article, "Zdziarski was one of the first software engineers to figure out how to hack the iPhone, and he's the author of a forthcoming O'Reilly Media book called iPhone Open Application Development, which gives readers explicit instructions on jail-breaking iPhones. So for Apple to give Zdziarski the podium at an Apple retail location is a little like Steve Ballmer inviting Linus Torvalds to speak at a Windows product launch." Zdziarski reports in his own blog how the open source community was on the iPhone developer scene as early as 2007, long before enterprises got there, and estimates that nearly 40% of all iPhones have been jail-broken to run the third-party community software installer. Finally, this story from Top Tech News suggests that open source software might actually create competition for Apple's "official" developers, because applications using the open source iPhone compiler are not subject to the same limitations as official Apple SDK programs are."