iPhone and iTunes Security

I don't own an iPhone, the Blackberry Bold suits best the way i work on the move, however i have been looking into various aspects of the iPhone as a development platform. I am a little concerned about the security aspects of some of the practices that the iPhone employs, not from an OS perspective, but from the view on how it interops with itunes.

From what i understand the MAC/PC to which the iphone is paired via itunes retains a complete image of the iphone's firmware on its hard disk. it sounds to me that someone with appropriate skills could take that image and retrieive data from it, also perhaps replace an image with a version laced with a self made keylogger.....Thus instant security breach

In fact this feature is the way that you can 'jailbreak' or hack your iPhone with a 3rd party firmware image. I am fairly new to the iPhone and the way it operates, could someone with more experience perhaps comment on this aspect of the iPhones operation?

I feel this means that itunes should be coded with tighter security or pin protection given it provides a conduit to the heart of the iphone.

As long as you don't leave your iphone connected to itunes AND unattended for long periods, i suppose this possible security issue can't be used by potential hackers. However with all the sharing features on itunes now available, how long before itunes becomes the target of hackers? Intresting subject matter that i would like more information on, which does not seem to be readily available from Apple,

Any iphone advice or links readily accepted......