Re-lighting this thread. I just got the iPhone and looking for good preparedness apps.

Here is what I have found so far that have been useful, (free).

AroundMe- using the phone GPS it finds you on a google map and then lists by category all pertinent businesses like hospitals, ATM, food/drink, gas stations, hotels, etc. You can also type in a general search. It then gives you directions to the address on a moving google map. I have used this many times already.

Just Light- turns touchscreen into a white light. Similar to white LED, good for general illumination. Used to find things that have fallen on the floor of the vehicle. Once to look behind a pc tower.

RK Free (run keeper)- Using your GPS it tracks your location and how far you travel in min/mile, mph, total time and total miles. Can be used for running but I use it more as a pedometer or confirming distances I walk.

I have been underwhelmed to say the least regarding actual GPS apps, free or charged. Also, as I understand, they work off the 3G network and not satellite so if I am out of cell tower range, its useless anyway. If this is incorrect let me know.

This has also kept me away from trail/hike apps. Change my mind if you can.