Three examples of linking to OpenWorldCat have just come over my horizon. Each represents a slightly different use, which is nice.

• A pilot with the Santa Monica public library catalog. Click on 'check nearby libraries' in the box on the left. An ISBN link with a zip code qualifier shows nearby libraries with the item. (Thanks to Migell Acosta.)
• Greenwood Publishing Group is direct linking to OWC from within their catalog. Check Basic Research Methods for Librarians, and click on the WorldCat logo to go through to the relevant Find in a Library page.
• Rag Bibliography. Click on the library link, where it is present.