We have seen some cool iPhone applications come out for shooting sports. But nothing comes close to the sheer awesomeness of the Knights Armaments M110 iPod Touch mount and accompanying ballistics software.
KAC contracted Runaway technologies to build an external ballistics calculator for the iPod Touch / iPhone named Bullet Flight. It is your standard ballistics application. You can set firearm / ammunition profiles, then call up the saved profile and enter your environment information, for example, distance, wind direction, elevation and temperature.
Full entry at The Firearm Blog