Here at PLU, biochemistry students make use of the RCSB Protein Data Bank for their research projects. It is "the single worldwide depository of information about the three-dimensional structures of large biological molecules, including proteins and nucleic acids." Students select molecules from the data bank to research, reporting on their structure and function.
Today, ScienceDaily reports that the PDB has added its 50,000th structure. (It began in 1971, with seven structures. What a difference 36 years makes!) And the nice thing, from a library resource as well as research perspective, is that all of this data is available to whoever wants to use it, free of charge.
Of course, someone has to pay for its upkeep, and actively maintain it, for it to remain a useful resource (currently, that's the job of the Research Collaboratory for Structural Bioinformatics). The Web is full of such resources, from large, government-funded databases to pet projects put together and supported by just a few people.
As I told a class of freshman writing students last week, you've got to look in more than one place to get your information: library research databases, but the open Web as well. The PDB is an example of how high-quality, up to date, useful information can be free--to its users, at any rate.