Just noticed that Lorcan Dempsey posted a similar blog entry about using greasemonkey userscripts to combine amazon with the library - in this instance, the University of Huddersfield library. When browsing books, users will be informed of whether the book is currently available at the university library, and a link takes you straight to the appropriate page of the catalogue. Amazing. I’ll not repeat the post again, but urge you to have a look yourself. And if you want to try it out, the script can be found here.