Has anyone heard of "Daniel Tammet"?

< Daniel Tammet is a British prodigious Savant (high-functioning autistic savant) gifted with a facility for mathematical and natural language learning.
Experiencing numbers as colours or sensations is a well-documented form of synesthesia, but the detail and specificity of Tammet's mental imagery of numbers are unusual. In his mind, he says, each integer up to 10,000 has its own unique shape, colour, texture and feel.
Tammet claims to speak twelve languages including: English, French, Finnish, German, Spanish, Lithuanian, Urdu, Romanian, Estonian, Icelandic, Welsh, and Esperanto.>

Which part of his brain is unusal and/or exceptional compared with those of ordinary people?

What kind of problems does he have?

http://www.youtube.com/watch?v=AbASOcqc1Ss

I've wondered if these special savants could break through the normal speed barriers to solving computationally-difficult problems.

For example, could this guy rattle off prime factorizations of million digit numbers almost instantly?

Here's an old discussion on the topic.

http://www.antimoon.com/forum/t12665.htm

There was also another discussion about this in 2007 or 2008.

I have seen two documentaries (or parts of two documentaries) on him.
I have only heard him speak French and English and some Icelandic.
His French was pretty good for an anglophone.

Steve Kaufman(n) of LingQ was asked recently about whether it was possible to learn a language very quickly in some short time frame Steve said, "no", and I tend to agree with him.

Tammett tried to learn Icelandic in a week. Speakers of Icelandic praised him, but I know very little about the culture in Iceland and whether people there praise all efforts in their language or not.