The University of Buffalo hosts an impressive number of case studies focused on science teaching and learning (378 as of July 21, 2011). The National Center for Case Study Teaching in Science offers educators in K-12 and college the chance to use their cases for free under some permitted uses.
The mission of the National Center for Case Study Teaching in Science at the University at Buffalo is to promote the development and dissemination of materials and practices for case teaching in the sciences. Our website provides access to an award-winning collection of peer-reviewed case studies.
The cases are available to everyone on their website, but educators must register to get access to the answer keys. Unfortunately, the current copyright licensing doesn’t allow you to modify the cases and is pretty restrictive in terms of hosting the file yourself, even in a protected space. See The Deforestation of the Amazon as a sample.
The use of case studies is often associated with problem-based learning (PBL), a practice the University of Delaware has been involved in for many years, through the Institute for Transforming Undergraduate Education. Rooms specially designed for PBL are available on campus for those interested in trying out this teaching method.