David Weinberger noted Tim Bray's nice post about the Bodleian a while ago. He discussed the catalog and went on to say:
So, for fifteen years a catalog was useful for browsing for books you did not know existed. After that, the catalog reverted to being a tool for inventorying stock and as a look-up table for librarians fulfilling requests for particular books. (Or so I understand it. Correct me, please!) [Joho the Blog]I left the following comment, but it does not appear to have been accepted onto the blog entry:
OK, I will bite ....
... yes catalogs do do rather more than you suggest. Sure, not all catalogs are made equal and libraries are increasingly aware that they can make the data in their systems work harder.
Some of the ways in which a catalog might unite the reader with items of potential interest.
Items by the same author
Click through the above title, and then click on the author Ernest Albert Savage.
Items on a similar topic
Consider the The Star Wars cook book : wookiee cookies and other galactic recipes. Click on Cookery -- Juvenile literature. Quite a nice list comes back.
Translations, other editions or versions of an item
Click on the editions tab at Reading in the dark to see several translations and editions.
Incidentally, clicking on the 'Northern Ireland -- fiction' link gives another very good list of items.
Items available in a library near you
Enter your zip code in the box on any of these pages, and then go through to the catalog (most times). For example, for libraries which have the World is Flat and are near where I live in Columbus, click here.
These examples all come from the WorldCat union catalog, built from data in catalogs in many thousands of libraries worldwide. Searches above are being run against Yahoo indexes of a subset of WorldCat. If you have an ISBN you can get through directly to a page. As with http://worldcatlibraries.org/wcpa/isbn/0738205435.
Maybe I emphasised Open WorldCat too much, but I wanted some examples and one of the advantages of OWC is that you can now do this kind of thing on the open web. It would have been more difficult to do it within a particular catalog.