Andrew Petersen, a lecturer in computer science at the University of Toronto at Mississauga, has posted a description of a system a summer intern built to anonymize student data. Basically, this system allows instructors to ask questions like, "Is success in the first-year calculus course a predictor of performance in a second-year algorithms course?" without giving them access to information about individual students. It's a good example of what Bruce Schneier, Latanya Sweeney, and many others are trying to figure out how to do in general: give those who need it access to information in general, while not compromising any one individual's privacy.