Wikitude (Free)
See the world with different eyes–your phone’s camera, that is. Wikitude is an “augmented reality” global travel guide that overlays Wikipedia and other user-contributed content over the phone’s camera view, giving you information on your surroundings.
Wikitude uses the phone’s GPS, compass, and movement sensors to match your position in relation to the landmarks you point the camera toward. The app works great as a tourist guide but also can be useful for finding the history of places anywhere around you.
Hotels Near Me (Free)

Using the GPS chip inside your Android phone, Hotels Near Me consults a 60,000-hotel database to find places to stay in your proximity. You get star ratings for each hotel, together with the address, phone number, and user reviews.
Once you pick a hotel, the app shows you photos of the rooms in a gallery and allows you to obtain price quotes for the duration of your stay. You can actually book the hotel room straight from your phone; you get an e-mail confirmation of your selection, too.
Hotels Near Me also lets you browse for hotels in advance of your trip: You simply select ‘elsewhere’ from the main screen and then enter your desired city.
Layar Reality Browser (Free)

The Layar Reality Browser, similar to Wikitude, is another augmented-reality browser app for Android that displays digital information on top of the images coming through your phone’s camera. You can add various “layers” to the image, such as information from Twitter, Wikipedia, Yelp, or the Brightkite geolocation app.
Where (Free)

Where is like the Swiss army knife of GPS apps. Using your location, Where gives you real-time information on cheap gas, weather forecasts, movie showtimes, restaurant recommendations, traffic conditions, and news headlines.
This great free app also lets you browse the Yellow Pages and the Yelp directory, and it even finds the nearest Starbucks for you. Just call it your new personal travel guide.
Yelp has an Android app for its service that’s similar to Where; it can add information from the directory on top of real-time images from the phone’s camera (as Wikitude and the Layar Reality Browser do).
Trip Journal ($2.90)

Trip Journal tracks your exact travel route by continuously recording your GPS coordinates, together with any photos you take along the way. This great travel companion also lets you add place marks and notes to your route, and gathers statistics on the distance you covered.
The user interface on Trip Journal is very sleek and easy to use. Once you’re back home, you can export your routes in Google Earth format to share with family and friends, and upload your photos to Facebook or Picasa. Trip Journal also lets you archive your trips for further reference.
If you’re not interested in sharing the pictures from within the app, go for the free lite version of Travel Journal.
FXware Currency Guide ($0.99)

A must-have for when you’re traveling abroad, the FXware Currency Guide lets you convert 160 currencies worldwide, with rates updated every other minute. You can invert exchange rates on the fly, and the app also includes a travel pocket guide with a quick conversion table.
FXware Currency Guide also includes a few other extra features, such as a tip calculator and a global currency quiz game; the more business-minded user can plot historical currency charts and check Forex market news and commentary.
StarTranslate (Free)

Can’t speak French? No problem! StarTranslate can help. This app is both a translator and a dictionary based on Google Translate, with over 50 languages available.
In StarTranslate you can enter text in English to get a translation in any of the supported languages (and vice versa). The program will even read the text out, when you press the speaker icon. Additionally, the app can translate SMS messages or send text translations over e-mail and SMS; all of the translation history remains stored on your phone.
TripIt (Free)

With the help of TripIt, you might never miss a flight again. Whether you’re about to take a short or long trip, you can send the arrangements to your TripIt online account and keep track of itineraries via the Android app on your phone, regardless of whether you are online or offline.
The free app gives you maps and directions based on your itinerary, plus information for hotels, airports, and restaurants; you can also dial phone numbers directly within the app.
WeatherBug Elite ($1.99)

WeatherBug Elite gives you advanced location-based weather information, including weather alerts, satellite maps, and cameras. The app doesn’t just show temperature information from the nearest airport, but also uses the WeatherBug network of weather stations to give accurate temperatures closest to you (using the phone’s GPS).
You can obtain weather forecasts for up to seven days (three days in the home-screen widget), with temperatures, wind speeds, humidity, and other details. WeatherBug Elite also shows animated radar maps and satellite views from Google Maps, and–most important–it alerts you in case of severe weather conditions.
Waze (Free)

Hear from fellow drivers where the traffic jams are. Waze crowdsources GPS information from drivers using the app on their phones; the results can help you avoid areas of high traffic, roadwork, accidents, and other obstacles.
Since Waze relies on user-generated traffic reports, the more people who use it in your area, the more accurate the information received is. You can also help other drivers in your area by notifying them of road problems via the free app, through text or picture reports.
FlightStats ($4.99)

Track your flights and trips with FlightStats. You can enter your trip details manually or import them from your TripIt account (optional upgrade, $1.99).
Besides flight information, you can add your hotel reservations or rental-car info; the app even works in offline mode, once synced. You can also check airport delays or find alternative flights in case you missed your scheduled flight.
Next…
