On the MotionX site, the FAQ section's answer to this question isn't very clear... Q10. Will the application work with an iPod touch or first generation iPhone if it is hooked up to an external GPS device? A10. At the time of this writing, TomTom and Magellan have the only Apple-approved external GPS modules compatible with the iPod touch and first generation iPhone. Other external receivers available currently require a jail-broken device. We will update the MotionX News Room if compatible devices become available. They don't say the Magellan and TomTom car kits aren't compatible. They just say they are the only Apple-approved ones. But this doesn't tell me whether or not they work with MotionX GPS Drive. Can anyone clear this up? The Magellan unit in particular says it works with any/most GPS apps. (In some places I've seen the work 'any' used, in others, I've seen 'most' used).