New from OCLC:
Now any Web site can create ‚ÄúFind in a Library‚Ä? links for specific titles. The syntax for link URLs is straightforward and keyed on common numeric identifiers.
For example: http://worldcatlibraries.org/wcpa/isbn/0459553224 will get you Mary Jane Sinclair’s Updating Statutes and Regulations etc., 1995 edition. If you want to set the URL so that only Canadian libraries (in the WorldCat program) that have the book show up, you would make it:
RedLightGreen has something similar, essentially a link to a targeted search (i.e. ISBN or title or author etc.), with the option in the results page to see if the book is in the library of your choice.