Brigadoon is a private island in Sl for a group of people with Asperger's Syndrome. For the uninitiated, Asperger's is an Autistic Spectrum Disorder. People with AS have difficulty in following the subtler aspects of communicating with people (picking up on double meanings, reading body language etc.) On the positive side, some people with AS may appear to be "geeky", having high level skills in e.g. Maths, or having an obsessive approach to a particular hobby or interest.
The Brigadoon project has been looking at using Sl as a means of communication for people with AS. The argument is that, because an Avatar does not have the same body language as a human (in fact an avatar has hardly any body language at all) then communication for someone with AS is that much simpler, as they don't have to try to deal with difficult body language.
Details of Brigadoon can be found at > braintalk.blogs.com