Apple's developers have high hopes to build for the iPhone US users eager to get their hands on an iPhone may have 29 June 29 circled on their calendars to mark the mobile device's announced ship date. But for software developers, the most significant date in the build-up to the iPhone's release was easily May 30. That's the day Apple CEO Steve Jobs took the stage at the D: All Things Digital Conference near San Diego and announced that his company is working to make its eagerly anticipated mobile phone open to outside developers, reversing months of skeptical statements about third-party involvement.