I found a great example of a volunteer program that has been developed by the City of San Antonio. The STAR program that they developed has connected undergraduate students around San Antonio with valuable service projects that have benefited the city. You can read all about the program here (http://icma.org/en/icma/knowledge_network/documents/kn/Document/304220/S...), and I imagine that the communities on the Community Relations and Citizen Engagement topic pages would be able to clue you into volunteer ideas that have worked for them.
Aloha, Best of luck,
Knowledge Network Intern