I spent a bit of time exploring Cambridge University's Autism Research Centre (ARC) website recently.  It's fascinating and helpful in so many ways.  ARC apparently has over 30 research scientists and support staff.  The website links to a series of freely downloadable research papers and assessment questionnaires.  One of the two directors of ARC is Professor Simon Baron-Cohen, author of many papers and books, including the popular "The Essential Difference: Men, Women and the Extreme Male Brain" which presents his theory that the male brain tends to be better at systematising, whereas the female brain tends to be better at empathising (although this isn't true for all men and women).  He goes on to suggest that autism (as well as its close relative, Asperger's syndrome) can be understood as an extreme version of the male brain.

The autistic spectrum extends from children who are strongly affected and can't function adequately on their own through to successful adults who may be doing very well in their lives but who struggle with relationships.  The downloadable tests can help to explain some of these experiences - for example by highlighting how one scores as a systematiser and as an empathiser.  This can also be helpful for therapists working with adults who have puzzling relationship problems.

Autism Research Centre.  http://www.autismresearchcentre.com/arc/default.asp  Accessed 10 September 2008.

Baron-Cohen, S. (2004) "The Essential Difference: Men, Women and the Extreme Male Brain"  Penguin  [AbeBooks]  [Amazon UK]