LibraryLookup
Jon Udell has created a bookmarklet generator that lets you jump from any Amazon book page to your local library's page for the same book, which makes reserving the book at your local library a cinch.

I created one for the Dekalb County Public Library and you can get it by dragging Dekalb County Public Library, Georgia to your bookmarks folder. And here's one for the Emory University Library.

This sort of thing just makes me happy to be alive...