Here are some ways to learn bits and pieces of the language while you’re on the road:

1. Read the signs.  Provided the country doesn’t use its own alphabet system (e.g. Japan), you can read what those signs say.  Right from the airport, you can probably figure out the local translations for male, female and restroom.  Do this every place you visit.
2. Learn the food.  Food is a common denominator across every culture.  When you hit a grocery or a market, point at stuff, trying to get vendors and staff to tell you the word for each.  Keep them in mind – they’ll be useful the next time you enter a restaurant.
3. Play with children.  Little tykes love teaching foreigners what they know of a language.  They won’t treat you like an idiot either (they’ll just assume you are – just kidding).
4. Haggle.  Don’t buy stuff at the first price you’re told.  Always haggle.  It opens up the interaction and you’ll learn plenty of words in the process (such as numbers, amounts and, if you’re lucky, numerous cuss words).
5. Be open to foreigners who want to learn English.  A lot of people the world over want to learn English.  Chances are, you’ll meet some of them during your trips.  Arranging for a “language exchange meeting” is common practice among English speakers traveling abroad.

Some people say you can learn a new language even without formal lessons, books or language software.  After all, we didn’t own a guidebook to learning to speak back when we were young.  Would it still be possible to try and learn, now as an adult, a new language without a formal guide?

Personally, I think you’re shooting yourself in the foot if you do so.  Young children are able to adopt languages early because the adults around them know that they’re still learning.  As such, they did not need to learn to speak in order to be able to communicate.  When they wanted something, they just cried – do you seriously think you can do the same?

While I won’t discount the possibility of learning a new language completely lesson-free, instruction gives you a good base to stand on.  Those memorized phrases, mundane as they may sound, will come in handy, especially when you’re immersing yourself in a place where the only language spoken is the one you’re looking to learn.  Using those simple phrases, you can get around, ask for help and provide information to those assisting you.

For the most part, I think it’s impossible to learn a new language without formal lessons as an adult.  You’re welcome to try, but I reserve the right not to look at the resulting disaster.