volunteering
Here are some case studies we found.
http://www.voluntarymatters1and2.org/people/volunteers/case_studies/index.html
http://volunteer.ca/en/search/node/motivation
http://www.commonimpact.org/work/#corp
Here is some other material on volunteering
http://www.energizeinc.com/art/atimevalue.html
http://www.independentsector.org/programs/research/volunteer_time.html
http://www.networkforgood.org/volunteer/
http://community.ups.com/philanthropy/toolbox.html#guidebook