This was a good read and I recommend it to anyone interested in learning languages.
About the book (taken from the site)
"If you've ever tried to learn another language, you know how much time, energy, and brain power is required. Imagine a person who can pick up languages very easily. Someone who can navigate our world's multilingual hullaballoo. Who can leap language barriers with a single bound. Who can learn without effort and remember indelibly. Such people aren't parrots. They're not computers. They're language superlearners.
Michael Erard searched for these people, and when he found them -- in history books and living among us -- he tried to make sense of their linguistic feats and their mental powers. His book answers the age-old question, What are the upper limits of the human ability to learn, remember, and use languages?"http://www.babelnomore.com/