Automatic Language Growth (ALG) started in Thailand as Dr. J. Marvin Brown built on Stephen Krashens' idea of maximum comprehensible input. His theory states that through exposure to language in a comprehensible context, we can acquire language fluency without the need to study rules.
In short, we learn like a native.
A friend, Brad writes about ALG, amongst other things at his blog about Payap University.
David Long heads the ALG Thai program in Bangkok and his site can be found at ALG World.
For my part, I am announcing that I have officially started my own language experiment: Mandarin Chinese.
I have no training whatsoever in the language. And while it's no ALG, access to Chinese TV is the best I have. I'll keep updated at milestones of 100 hours, 200 hours, etc of my progress. My goal is to achieve 1000 hours over the next 4 years.
Let the games begin.