If you want to be an expat, there’s a good chance that learning a new language is going to be important. Rather than pay for overpriced, overhyped language tools, you can have a far lower budget and get better results by knowing where to look on the internet (there’s at least one language software package out there which is famous, expensive, absolute rubbish and will suck you in due to the sheer force of its advertising budget. Do some digging and you’ll find it).
Lingala, for example, is an obscure (outside of Africa) African language. Joshua Foer learned Lingala in 22 hours. Now, before you cry foul, read the article. In short, Joshua used a site called memrise and spent a few minutes a day over a span of about three months. Though hardly fluent, he learned Lingala well enough to communicate with native speakers.
Joshua claims to not be skilled with languages, but memrise uses a technique called spaced repetition (along with bizarre memory associations) to help you memorize things. Serious language students have been heading to the site in droves. There's a huge amount of research out there on what helps people learn and memorize things better and while our school systems are largely ignoring much of this research, the Web is not and that's to your advantage.
Due to the nature of spaced repetition, when using memrise you can't "cram" for a language and are forced to spread out your learning over time. Fortunately, this means that you don't burn out too quickly. So far, I've already found myself in a French conversation where my studying on memrise has paid off. memrise is a relatively new site and they're still improving it, but so far it's great.
You still don't believe me? Try the Guardian Challenge. In 10 short steps, you'll learn how to order off of a Chinese menu ... in Chinese! You'll be able to order 鸡蛋炒饭 without a second thought and can decide for yourself whether or not memrise is for you.
Another new site, one I've not tried but which is also popular amongst language geeks, is Duolingo. Sign up for your free account there and you will be tasked with translating Web pages. You'll only be shown text at your level and as you improve, you'll get progressively more complicated texts. Instead of learning individual words, you'll be burning the grammar into your brain and really learning how to read.
While I'm not a fan of Lifehacker (mainly due to its being part of the Gawker network), they do have some interesting articles about language learning. One is I learned to speak four languages in a few years. The author claims his method has gotten him to C1 (advanced speaker) language proficiency in five months (that's stretching credulity a bit). Just about everything he says seems to ring true, but I'd be tempted to replace the Anki deck with memrise.
Another great article is How I learned a language in 90 days. It also has plenty of great advice. The author does not claim that you'll be anywhere close to fluent in three months, but following his advice, you should know about 3,000 words in the target language. Depending on the language you choose, 3,000 words is going to cover about 75% to 85% of the words in common use for a given language. That should allow you to at least get by in most situations.
But so what? You're moving to Rotterdam and you're told everyone speaks English. Or your going to teach English in South Korea and you're told that you don't need to learn Korean.
Never is not a word I like to use casually (unlike "bullshit", apparently), but if the native language isn't English, you can never truly integrate unless you understand that language. How do you handle that recorded voice on the phone? What do you do if your bank's Web site isn't translated to your language? How do you feel when you're at a party and your local friends break out Youtube and are all laughing at something that you can't understand? You're sick in the middle of the night, it's an emergency, but you don't know how to call a doctor. What then?
Learning the language not only makes your life easier, but it also makes it easier to understand the culture. There are plenty of things in both English and French which don't translate well into the other language, but once you learn them, you'll gain a better insight into your new world.
If you decide to get serious about learning a new language, start hanging around the language learning community (Reddit's /r/languagelearning is a good start) and pay attention to what's going on. You'll quickly learn that serious learners find spaced repetition invaluable. Using that to master that first two to three thousand words will give you a great start. I would recommend starting with Pimsleur courses to get a good handle on pronunciation and grammar (it uses a variant of spaced repetition), along with memrise to supplement some of the writing and vocabulary deficiencies of Pimsleur. Stick with this approach and you'll be up and running in no time!