The Data And Stories Library (DASL) is a library of real world datasets and associated stories that is searchable by Method, Subject, and Topic. Quite handy for finding examples of applications of different techniques.
Gapminder is a neat organization founded by a passionate Swede (there are such things!) and devoted to making accessible and visualizing lots of social, economics, health and environmental data from countries around the world. The data come from the UN, World Health Organization, FAO, World Bank and other international organizations. A searchable database of datasets is here: [www.gapminder.org/data/].
pirates.txt This data set correlates global temperature and pirates. It is originally compiled by Bobby Henderson (The Church of the Flying Spaghetti Monster) in his Open Letter to Kansas School Board in protest of teaching intelligent design as a substitute for evolution. It may be used in an elementary data analysis class to illustrate the concept that correlation does not imply causation.
ants.csv This data was used in QERM 598 for simple two-sample comparison tests. This original data comes from two accompanying data files from a study on the foraging habits of two species of ants: thatch ants (Formica planipilis) and seed harvester ants (Pogonomyrmex salinus). The original two files submitted by Peter Nonacs, can be found at the UCLA Data Library.
See the Ocean Colors page for ways to access satellite derived primary production estimates for anywhere on earth on a relatively fine scale over the past ten years.
Eli_bath.txt - Bathymetry data from the Sea of Okhotsk obtained from NOAA at http://www.ngdc.noaa.gov/mgg/gdas/gd_designagrid.html. See how to integrate this data with the R map functions at the Bathymetry data page.