A couple of years ago I came across what I think is one of the best free language learning sites on the internet. 

If going to Afghanistan, and are interested in Learning Afghan Dari or Afghan Pashto, you may still be able to download 600mb worth of Pimsleur at no charge from from USO http://www.uso.org/operation-speak-easy.aspx   (Alternative Pay site @ $345 USD:http://www.pimsleur.com/Learn-Dari-Persian/Dari-Persian-Comprehensive/9780743571548) US Only.

The website features dozens of languages, using a unique learning method which I think is great. Its based around listening to 20 Minutes of the top 3-400 words of a language, spoken by a native speaker, which you repeat and copy once a day, it suits my style of learning and the time periods I have available to learn. Its not a "complete" course, but gives the basics and thats all I want to know for now. 

If you use the Flashget addon with your web-browser you can download the entire series, with Mp3 audio and the books as word documents. There are links to a website where you can buy a printed copy for $5 or so. 

Below I have attached a few that I liked:

Dari, Farsi, Tajik, Iraqi Arabic, Kurdish, Pashto, Serbo-Croat, & Urdu.

Download the associated MP3s here: http://www.crelearning.com/lang.htm