You can also tag books within a personalized section of Amazon called Your Media Library:
#www.Amazon.com/gp/library#
Here you can view all your previous purchases and buy online access to eligible physical books you've purchased from Amazon. You can organize your Media Library by tagging individual books:
Click on the book to select it. Bibliographic information will be displayed at the top of the screen.
Any currently used tags for the book will be displayed just below.
Click the Add button to enter tags. If you've created other tags previously, a list of similar tags is shown below the edit box.
Type in a new tag or click a suggested tag and click OK to save.
Once you're using tags, try to be consistent, using the same tag to designate the same association. For example, don't use both "art deco" and "artdec" to tag the same kinds of things. For help, consult the list of your most frequently used tags, which pops up when you're tagging.
Although it's relatively new, Media Library could become the hub of Amazon's social-networking strategy, an avenue for readers to connect with others who have common interests.