TripIt - TripIt is a travel app that creates a master itinerary to organize all of your plans for your vacation or work trip in one spot.
Foursquare - Foursquare is all about helping you find new ways to explore your city.
Sygic Travel Maps - Itinerary planner for independent travelers
Tripadvisor - The Tripadvisor mobile app is available for the Android and iOS platforms. It can be used to create reviews of hotels, restaurants, and to chat with other travelers on Tripadvisor forums.
Travelchime - Google Docs for planning your trips with friends.
Yellow Pages - YP.com local search connects you with over 19 million local businesses.