There are many organizations that focus on sociological issues. Sometimes people with sociology degrees go to work for these types of groups. Drive by agony is an organization that works endlessly to combat gang violence.
Sociologists also focus on environmental issues.
Heal the bay and the surfrider foundation both deal with issues that impact the beaches and oceans. Sometimes sociologists work with environmental groups such as these. If you are interested in participating in non-profit organizations, Habitat for humanity is a national program where volunteers build houses for people who are unable to afford their own homes. I strongly suggest that you pay them a visit. You can find a comprehensive list of these types of organizations on the Ohio Domestic Violence Network .