TripIt - Travel Organizer (no ads) Store your travel details on-line. You don't need to have your travel information printed.
The app is connected with your e-mail and will put all details into an organized itinerary.
AroundMe Using your location it shows you many things around (nearest gas station, restaurants, places of interest). It has GPS driving instuctions which are very
Yelp If you are in a new city, this app is very useful. It gives you users reviews for many places, photos and ratings. Which restaurant
has free Wi-Fi, what kind of food they provide, etc.
Urbanspoon A good app to select a place to eat. With the iPhone app you can book restaurant recervations.