Sometimes, it only takes a few words in a foreign tongue for a traveler to endear themselves to local people. At the very least, knowing how to count in the language of the country you are visiting can help with bargaining for goods or, perhaps, an un-metered taxi ride.

There are some good resources on the internet for learning the basic structures of a language. Here are my humble recommendations:

Online: UCLA's Language Project offers profiles of pretty much every major language in the world. Have a list of study materials available. The National Translation Service offers a similar site, only with cooler design and simpler navigation. Omniglot gives a brief summary of languages, including a decent amount of coverage of various writing systems, and links to leaning materials. With a little exploration, it is possible to get the basics of a language without having to run up your credit card bill on Amazon (or, if you are old-school like myself, at the local bookstore).