How about setting up an account on Goodreads or Shelfari to list the books on your Kindle? I believe with Shelfari, you can import your Kindle books from your Amazon account.
Or a spreadsheet on Google docs?
I keep all of my ebooks in lists in
Delicious Library and
Calibre, as I have a lot of ebooks not only from Amazon but many other sources. None of my methods are perfect, which is why I cross-reference them between these two app and Goodreads.