It only works with Google Chrome browsers right now but this looks good . . .
Browser Extension Encourages Amazon Searchers to Head to Their Library | LJ Insider
“Avid readers who have made New Year’s resolutions to visit their local library more often might be interested in the Library Extension for Google Chrome. The free extension lets users know whether specific books, ebooks, audiobooks, and music CDs are available at their local library while they browse for those titles at Amazon.com.
[The full article includes an interview with] Seattle-based software developer Andrew Abrahamowicz…
Catalogers visiting Amazon might have noticed that the print books section of Amazon’s website is organized by ISBN number. URLs typically begin “amazon.com/gp/product/ISBN.” Similar to bookmarklet programs such as LibraryLookup, this Chrome extension works best when it can capture that ISBN number ….
“The accuracy of the result may depend on the individual library and what catalog they’re using,” Abrahamowicz said. “Some libraries will have lookups by the ISBN, in which case, I can have it do a direct lookup based on ISBN. If a library doesn’t have that capability, or if it happens to not find the ISBN [on the Amazon site], it will try to do a title match as best as it can.”
If a title is unavailable, the program will also offer suggestions for other titles, or in the case of audiobooks, suggest that the user try searching for the title in a different format. …
…The Library Extension site includes a support link where he encourages users to send feedback, including comments, suggestions, bug reports, or requests to add support for additional libraries.”