Americorps is another option for post-graduate development. From http://www.nationalservice.gov/programs/americorps:
AmeriCorps engages more than 80,000 Americans in intensive service each year at nonprofits, schools, public agencies, and community and faith-based groups across the country.
Since the program’s founding in 1994, more than 800,000 AmeriCorps members have contributed more than 1 billion hours in service across America while tackling pressing problems and mobilizing millions of volunteers for the organizations they serve.
There are tons of opportunities available for americorps volunteers – start at the Americorps website and search by your interests!