Hey guys. I just got a ballistics calculator app on iTunes for my iPhone 3G. It's got a ton of pre programed popular loads and can be easily customized for your handloads. It also gives you the adjustments for temp, wind, humidity and LOS angle. All of these can instantly be adjusted in the field and the GPS aspect of your phone will give you the weather conditions at your location. I haven't used it in the field yet, but it matches well with all of my paper ballistics charts. The app also has a decent MilDot range calculator, graphs, and a range log.