[I asked my friend Gary Moskoff to answer this one as his company has developed an Apple iPhone application that addresses just what you're talking about: iHound. Here's his response]

Hello, my name is Gary, and your question keeps me and my team up at night.  Your problem is exactly the issue. In fact, as intelligent mobile devices proliferate, and individuals such as my mother want an iPhone, I lie in my bed awake thinking of all of the "things" that can go wrong when she begins to depend on her device. 

My mother is not technically savvy, and although I am excited that everyone wants an iPhone, is that wireless, mobile, "hip" lifestyle safe for everyone?  Having owned an intelligent device for years, I have also become very aware of what information I am storing on my device, plus how and where this information is being stored.  

As individuals everywhere begin to migrate to a mobile lifestyle , I implore everyone to be more aware; more aware of your devices, the information you are storing on them and how you protect them.  

For this reason, we created iHound Software. iHound provides a mobile security solution, which if used in conjunction with our security guidelines as outlined on our website, will help secure your mobile device from being lost or stolen and will help you keep your data secure as well.

iHound can help you find and recover a lost or stolen Apple iPhone and/or iPod Touch by using the GPS and wifi signal built into your device to determine its location. That location is then reported to the iHound server, then, using iHound Software's tracking website, you can identify the exact location of your iPhone or iPod Touch.

I think that there are two reasons to check out iHound:
• It makes common sense to protect your iPhone investment.
• iHound helps increase your chances of recovering your lost or stolen iPhone, iPod Touch and/or mobile USB device.

I strongly encourage you to change your habits and follow the easy-to-use security tips outlined on our site.  Some of what we suggest may seem a bit odd in the beginning, but if you install iHound on your devices and follow our security tips, then the chances of your mobile lifestyle backfiring and all of your personal data being stolen is reduced dramatically!  

Would you leave your front door unlocked or, for that matter, the door to your car?  Of course not, so why do consumers leave their smart mobile devices unlocked and unprotected?

Prior to developing the iHound app for the iPhone and iPod Touch, we also developed a free security solution to protect your USB devices, alerting you when your USB digital device is connected to another individual's computer when that computer is online. This solution remains free today and the team has decided to continue offering this version of our USB solution for free for the foreseeable future. Learn more at iHound Software.com.