Post-graduation Opportunities
Numerous post-graduation service programs exist that allow college graduates to get involved both nationally and internationally. Some pay participants a stipend and others require a volunteer fee to cover housing, training, etc. The programs below are a sampling of options (not endorsements) - make sure to research the programs carefully and ask for references of past participants to make sure the program is a good match for your interests.
National Opportunities
AmeriCorps is a network of national service programs that engage more than 50,000 Americans each year in intensive service to meet critical needs in education, public safety, health, and the environment. AmeriCorps members serve through more than 2,100 nonprofits, public agencies, and faith-based organizations. They tutor and mentor youth, build affordable housing, teach computer skills, clean parks and streams, run after-school programs, and help communities respond to disasters. Created in 1993, AmeriCorps is part of the Corporation for National and Community Service. Post-graduation service opportunities are available throughout the country, typically a year-long with stipend and education award. Check out VISTA, AmeriCorps, and NCCC programs.
City Year unites young people of all backgrounds, ages 17-24, for a demanding year of community service and leadership development in 16 U.S communities (Cleveland, Boston, Seattle, Washington DC, NYC, etc.) and Johannesburg, South Africa.
The Citizen Schools National Teaching Fellowship offers a two-year, three-pronged leadership development experience: service as a team leader at a Citizen Schools campus, professional development with a partner organization in the community, and optional enrollment in a pioneering Master's program in out-of-school learning. The Fellowship is designed to provide hands-on leadership development to people of varied backgrounds who have high potential as educators and community builders.
The Fellows Program in Public Affairs is a nine-month, full-time, post-graduate experiential leadership training program which introduces diverse, intelligent and driven young public servants to all aspects of the public affairs arena. Field assignments, site visits, interviews and special individual and group projects and consultancies prepare Coro Fellows to translate their ideals into action for improving their own communities.
Inner-City Teaching Corps >>
Based in Chicago, the mission of the Inner-City Teaching Corps is to transform education in underserved communities and to empower children in urban schools through innovative education opportunities.
Jesuit Volunteers work in the United States and in six countries with hundreds of grassroots organizations to provide essential services to people who are homeless, unemployed, refugees, people with AIDS, the elderly, street youth, abused women and children, the mentally ill and the developmentally disabled. JVC has become the largest Catholic lay volunteer program in the country.
SCA members help protect vital habitats, do wildlife research, provide education, and build backcountry trails in national parks, forests and urban green spaces. Hundreds of environmental positions from Alaska to Yellowstone, from the Grand Canyon to Cape Cod.
Teach For America is a national corps of recent college graduates of all academic majors who commit two years to teach in urban and rural public schools, and become lifelong leaders in the effort to expand educational opportunity. 
International Opportunities
Cross-Cultural Solutions is a leader in the field of international volunteering, with over 3,000 volunteers each year. Founded in 1995, they are an international not-for-profit organization with no political or religious affiliations. CCS has a worldwide staff of over 200 people, and operates in 12 countries. Volunteer internships also available.
Cultural Embrace >> 
Cultural Embrace's mission is to encourage people to recognize and appreciate cultural diversity. Their team is a community of well-traveled educators who want to share their passions traveling abroad with you. If you want to teach, volunteer, intern, learn a cultural activity or take a tour, Cultural Embrace has a program that is customized to fit your schedule, needs, interests and budget.
Jesuit Volunteers work in the United States and in six countries with hundreds of grassroots organizations to provide essential services to people who are homeless, unemployed, refugees, people with AIDS, the elderly, street youth, abused women and children, the mentally ill and the developmentally disabled. JVC has become the largest Catholic lay volunteer program in the country.
The Peace Corps traces its roots and mission to 1960, when John F. Kennedy challenged university students to serve their country in the cause of peace by living and working in developing countries. Since that time, more than 182,000 Peace Corps Volunteers have been invited by 138 host countries to work on issues ranging from AIDS education, information technology, and environmental preservation.
Unite For Sight empowers communities worldwide (particularly in Asia and Africa) to improve eye health and eliminate preventable blindness. Unite For Sight's volunteers range from undergraduate and medical students, educators, nurses, and public health professionals to optometrists and ophthalmologists. The volunteers serve as interns at partner eye clinics and participate on community-based screening programs. Short and longer-term volunteer options.
Extensive opportunities to search by country or volunteer activity. Just make sure you research the reputation of any particular group.
WorldTeach provides opportunities for volunteers to teach in developing countries, making a meaningful contribution to schools and communities that are in great need of teachers. Most volunteers teach English and students range in age depending on the placement. In some countries, volunteers may also teach math, science, computer skills, or HIV/AIDS awareness.