Schemer - Google’s test crowd sourced travel guide.  Users leave recommendations for things to do in their city and visitors can add to a to do list and check off as they go.
iMuseum - A web tracker that searches via GPS the closest museums in your immediate area. Updates museum news and exhibition info regularly.
Air Sharing - Turns your iPhone into a wireless hard drive, allowing the user to quickly load documents at the airport that can be viewed in flight.
Ski & Snow Report - Get the latest ski reports with detailed trail maps.
Tripit - Combine all your travel reservations in a single locations.
Google Maps - Accurate GPS enabled maps along with voice navigation.
Schemer - Users leave recommendations for things to do in their city and visitors can add to a to do list and check off as they go.
Perfect World Clock - Provides easy access to the time in hundreds of cities adding several clocks as home screen widgets.
Livingsocial - Find 50% off restaurant offers.
EveryTrail - Track, share and explore.  Plot your trip, photos, and video right on the map and upload it to EveryTrail, Facebook, and Twitter.
Pin Drop - Allows users to drop GPS pins onto a map while traveling of interesting spots or review user made lists recommending the best sights, sounds, and flavors in town.
Zagat - A guide to discovering the best restaurants, bars, cafes and clubs.  Started with nine cities (Austin, Boston, Chicago, London, Los Angeles, New York, Philadelphia, San Francisco, Washington DC) with more on the way.
HopStop - Offers public transport information on 68 of the world’s biggest, busiest metropolitan hubs.
Where To? - Enables user to locate almost anything nearby, including the nearest ATM, burger joint, and medical provider. 
Wi-Fi FInder - Directions to your nearest source of wireless internet. Comes with an offline mode so that users can download maps.