From the site:
The aim of the conference is to break down the barriers between disabled users and the social web as much as giving ethical hackers real world issues to solve. We talked about improving the accessibility of the web for a long time - let's not wait, let's make it happen.
A lot of companies have data and APIs available for mashups - let’s use these to remove barriers rather than creating another nice visualization.
And on a random Friday night, this is a fascinating post on Facial Recognition in Digital Photo Collections: "Polar Rose, a Firefox toolbar that does facial recognition on photos loaded in your browser."