Live in Japan! (Score 1)

Yes. That is *the* best method. Because it is basically "Do or Die."

I lived and worked in Japan for 7 years. Fortunately, I had the language skills already. For those foreigners around me who did not, I noticed that within 1 year they were able to comprehend most daily conversation and even speak basic language.

Remember, it's all about communication. NOT about grammar, rules, etc. Seriously, get a job and live in Japan. Especially the Slashdot crowd should *not* have probs getting a job with all the IT postings available in Tokyo. Good luck!