to be honest i dont think you need to worry too much about this, although the iPhone has recieved plenty of air time and attraction i dont see that it will be wanting to be hacked anytime soon, similar to the mac, its too small of a target to mean anything except to the odd hacker out for a good day (as it were).
i can tell you though apple have throughly tested the iphone security the new version is mopre secure and has had multiple hacker sessions to try and beat its security, it is very safe.

hope this helps