Here is a link to the Scots-Irish DNA Project which has information on the project and links to both the 'Join' page and the 'Results' page. I post this in response to several hundred inquiries I had asking for this. The Scots-Irish DNA project has grown very fast and is approaching 1,000 participating families. A lot of very good information there for family historians and genealogists. Most of the participating families list the oldest known ancestor of their family. This allows of researchers to use this data and cross reference to see if a connection can be made.
Many families discover cousins they did not know they had. Then they will triangulate their data. Often a very complete history of a family will emerge from this process. Many participating families have located their kinfolk in Ireland and Scotland and reconnected their families.
Link: The Scots-Irish DNA Project