Sit or Squat - This app, sponsored by Charmin, has lots of user-generated content and uses your location to help you find the closest bathroom. It even ranks them as clean (sit) or not so clean (squat).

Taxi Magic - Sometimes, when traveling with kids, it's time to go and time to go home now! When wrangling kids on public transportation isn't an option, this app can connect you with a local cab company so you will always be able to get back to your hotel.

Word Lens - This app isn't only handy, but it's entertaining. Buy one of the foreign language dictionaries for $5, point your smartphone camera at any text and it translates it in real time in the photo on your screen. It works best with plain type faces, like public signs—so you'll never find yourself wondering whether that sign says "Park here for good eatin'!" or "Park here to be eaten!" (It could happen.)

Google Goggles - This is a really cool app that's still being developed so I think it will have more uses in the future. Right now point your smart phone at a landmark building or other image and it does a google search on the image! Find out what that cool building is, discover more about the bottle of wine you're drinking, translate text, and more all by snapping a photo.

XE Currency - Everyone needs a good free currency converter.

Google Maps - I use google maps all the time. It can give you directions by foot, car or public transportation, help you find restaurants or stores nearby, show you what a place looks like (want to know if your hotel is on a grimy back alley or a swank boulevard?) and recently they've added maps of indoor destinations like major museums.

Yelp - Has real people reviews of restaurants and stores, but one thing it can be particularly useful for is finding a doctor or a dentist in an emergency when traveling. User reviews help you at least know the person is decent, better than closing your eyes and pointing at a phone book page.