If you want to do voluntary work in Brittany, meet up with other people working for the same cause or people involved in France and the rest of the world, visit the website of the Chantiers Internationaux de Jeunes Bénévoles de Bretagne:

http://www.chantierbenevolebretagne.org/

These projects provide the opportunity to meet young people from all backgrounds and cultures regardless of religious and political beliefs. You will be working together towards a common goal, be this restoring a site, developing a community or rehabilitating a location. This is also the chance for you to learn to live in a community and learn techniques and skills which will be of use to you in the future.