Tomtom or GPS Software on iPhone 3G

As for what is coming nobody really knows...but google maps is the only current solution, and that does not provide turn-by-turn.
I personally think that nothing beats a dedicated SatNav device, the antenna on a dedicated device is better and the receiver can pick up a weaker signal and aquire satelittes faster.
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Agreed. iPhone is for those that dont want to spend the extra money or dont need a real Sat turn by turn. Im in that group! iPhone with Maps meets my needs.
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I agree with Greg. Casual navigation (where is the nearest Apple Store) is about all that the GPS applications are designed to do.
Search these forums for a wealth of GPS Navigation threads, no point in repeating them here.
Go out and get a Garmin. Even if the iPhone worked as a Personal Navigation Device you would never have all the features that a Garmin/TomTom has, and the screen is too small, the processor too slow, the battery too weak, an the OS too restrictive to do a good job as a PND.
Unless Apple makes a deal with TeleAtlas (TomTom) its not going to happen. Navtec, the only other map source, is owned by Nokia. I dont see them falling all over themselves to help a competitor.