For iPhone app developers the year's biggest event is undoubtedly Apple's Worldwide Developer Conference, but it is not the only event with a focus on creating apps for the iconic handheld devices. Earlier this month, nearly 600 people gathered at the Yahoo campus in Sunnyvale, California, for iPhoneDevCamp 3, the third installment of what has become an annual BarCamp-style conference where the participants are also the organisers and presenters. The first iPhoneDevCamp was held in July 2007, soon after the original iPhone debuted, and focused on developing web apps. iPhoneDevCamp 2, held in August 2008, revolved around the native apps made possible by the iPhone 2.0 software. This year's conference continued that focus, adding coverage of features and opportunities provided by the recent iPhone 3.0 software update. In addition to the in-person attendees, many more developers took part in the weekend's activities through satellite locations in 10 cities, including Chicago, New York, Austin, Boston, and Munich. These locations were able to participate via video feeds; there was even an iPhone web app for choosing and viewing feeds. The highlight of the weekend's activities, was Sunday afternoon's Hackathon contest. Clearly inspired by the Best Hack competition held over the years at MacHack, Hackathon is a contest where developers try to come up with the best iPhone apps – from idea to working software – over the weekend. Each team of developers was given three minutes to present their app, with the winners chosen in a wide range of categories, from Best Open Source to Ironcoder, the latter given to the app that makes the best use of particular APIs. Over the course of three hours, the judges saw demos of more than 50 new iPhone apps. Here are a few highlights: Foodspotting Lite; winner of the Best Social App award. This is a clever app for foodies that lets you search for dishes rather than restaurants. Nurse Brain; winner of the award for Highest Potential Startup Idea. This an app to ease nurse shift transitions in hospitals. The app provides a "dashboard" with information on every patient under a nurse's care. CarPark; the unanimous winner for Most Useful App. This is designed to help you remember where you parked your car and avoid getting parking tickets. When you park, the app tags your location, using the iPhone's GPS feature, to make it easier to find your way back. MockUp is a tool for creating mockups of iPhone-app interfaces. The app's built-in library includes all the standard iPhone-app interface elements – buttons, menus, text areas and so on – and lets you place them on an iPhone-screen template. Panelfly is yet another comic-book reader for the iPhone, but impressive because of its great interface. It features a panel-by-panel reading mode where a tap on the screen advances you to the next panel – where "next" is defined by the comic creator, not the app.