http://www.solipsys.co.uk/new/LearningLanguages.html?HN
I went to the local shops and bought a copy in Bulgarian of "Men At Arms" by Terry Pratchett, and I set about decrypting it.
As you might expect, I didn't really get all that far in four days, but I was able to go to the local shops and order coffee, comment on the weather, reply to questions about my work, and read the menu. I could also do some actual shopping, with considerable tolerance from the vendors, no doubt, but without anything other than Bulgarian and good will.
We had a formal dinner at the end, and as the Rear Admiral came down the line shaking hands I said "Blagodarya" (can't write Cyrillic) and he stopped dead in his tracks. "You speak Bulgarian?" he asked, in tones of great surprise. "Only a few hundred words - I've only been here 3 days" was my reply. He proceeded to quiz me on common phrases, and seemed surprised and impressed.
Later, when we all got a "Thank You" email, I was the only one whose email was personalised. More, even though that contract was never awarded, we have since been contacted to start negotiations for other work. Clearly the episode made an impression.
Sadly, after leaving I didn't have the chance to continue practising and I lost it all quite quickly, but there was a magic period of a few hours where I was really getting the hang of communicating (comprehension was significantly better than synthesis), and it has made me regret again my mono-lingual background.