Groupon - Find 50% to 70% off restaurant offers.
XE Currency - Quotes live currency rates.
Google Wallet - Send money from anywhere to a friend in the US who has an email address.  Store loyalty programs in Google Wallet and leave the plastic cards behind.
Foodspotting - Focuses on specific dishes with user generated recommendations.
AlpineQuest GPS Hiking - Comprehensive orienteering maps come complete with contour lines.
Packing Pro - Enter destination, length of trip and who with and it will provide a list of what you may need.
FlightAware - Track your flight by entering your airline and flight number and receive updates on flight delays, gate changes, and/or cancellations.
Evernote - Take notes, capture photos, create to do lists, record voice reminders, and make these notes completely searchable. Users can combine and share travel notes.
JetLag Genie - Gradually alter your sleep habits before a trip to better deal with jet lag.
Opentable - Reserve tables and earn rewards at over 20,000 U.S. restaurants.
Urbanspoon - Shake your phone and the Urbanspoon slot machine will suggest local popular east via the GPS in your phone throughout the US, Canada, UK, and Australia.
TripAdvisor - Honest reviews of hotels, restaurants, attractions, and more.
Google Goggles - Search by taking a picture. Users can point their cell phone cameras at paintings, famous landmarks, barcodes or QR products, or popular images. If Goggle finds it in its database, useful information will be returned.
Tipulator - Makes tipping easy even with split bills.
EHU - Helps campers and caravanners keep track of the electrical output of their assorted travel gadgets to avoid overloading the circuit.