The Data and Story Library (DASL) is an "online library of datafiles
and stories that illustrate the use of basic statistics methods.":
http://lib.stat.cmu.edu/DASL/
The Chance Database: "This data base contains materials designed
help teach a Chance course or a more standard introductory
probability or statistics course." http://www.dartmouth.edu/~chance/
Dr. B's Wide World of Web Data: "This archive is a set of links
to data and depcitions of data from throughout the world. It is organized
by topic areas. We hope instructors will use these data for examples in
classes AND set students loose to find data that THEY find interesting."
seamonkey.ed.asu.edu/~behrens/siip/webdata/index.html