Amazon is not just a great repository of books, it is also a fantastic repository of book covers. The book cover images displayed on the Amazon webpages are usually pretty small and have text and graphic overlays on them. For example, "Look Inside!" or "30% Off!" and so on.
For example, the cover image of a David Copperfield book on Amazon looked like this:
The book cover URL was found to be:
The full-size cover image without any of the overlays can be obtained by modifying the image name. Remove all the text in the image name from the first period (.) upto the file extension. So the above URL after modification becomes:
With this modified image URL, the full-size image can be obtained from Amazon:
This works for all images at Amazon: books, CDs, DVDs and so on. For more information on the image URL format used by Amazon see Abusing Amazon Images by Nat Gertler.