Check out (works on on FireFox) this very cool XUL app to search books on Amazon. http://www.faser.net/mab/chrome/content/mab.xul

XUL (XML User Interface Language) is a user interface markup language developed to support Mozilla applications like Mozilla Firefox and Mozilla Thunderbird. Like UIML, it is an application of XML that describes user interfaces. The acronym is pronounced zool, to rhyme with “cool”.