This past weekend I had the opportunity to test the TomTom app. I started in southern Ohio and navigated to Crossville TN. approx 350 miles one way. My phone is a iPhone 3G JB w/numerous apps downloaded from Cydia, including Backgrounder. First off, a couple of things I noticed while navigating... -TomTom is slighty less accurate in positioning compared to Navigon -TomTom is less detailed, and slightly slower, on the actual "turn-by-turn" voice instruction (which is important and I'll talk about later) -TomTom seems to use less available memory than Navigon..likely to vary TomTom's average free memory w/ipod playing= 11 MB Navigon' average free memory w/ipod playing= 8 MB -TomTom is faster in finding and acquiring routes from a fresh startup. Now, I have read numerous concerns about safe navigation while using turn by turn....In my opinion, Backgrounder is the answer. On the trip home I backgrounded TT and when I got in the city parts, I let the voice alone guide me. This allows you to keep your eyes and most of your mind on the road. It was less stressful than constantly looking down at the Phone to see your route. If you get off track, it's very easy to open the app and it shows right up where you are within a half a second, even on low memory. Most probably already know all of this, but for those who are "on the fence" or concerned about safety, this might help them make that decision once and for all. FWIW, I drive a Silverado and using the method I described its similar to using Onstar except with the phone you obviously have the opportunity to see the route.