Xenoglossy : Xenoglossie or Xenoglossia are the terms used to describe the ability shown by a child or individual who can write or speak a language they could not have learnt by natural means. In many cases Xenoglossy is referred to as a paranormal phenomena but it is also one that can manifest itself after the individual has experienced head trauma like a car accident and x-rays of these individuals brains have exhibited neural pathways being used that may not have been used prior to the accident.
There are ongoing studies into this phenomena and it is certainly one that is worth further investigation although I doubt anyone would want to experience a major head trauma even if the compensation was the gift of a new language or ability!
The following videos on Xenoglossy include discussion, documentaries, interviews and demonstrations.