LIBRARY THING

1. Take an ISBN, like 0545010225
2. Put your Developer Key and the ISBN into a URL, like so:
   http://www.librarything.com/devkey/KEY /medium/isbn/0545010225

http://covers.librarything.com/devkey/KEY /medium/isbn/0545010225


http://www.librarything.com/search.php?term=science&searchtype=groups  

http://www.librarything.com/search.php?searchtype=talk&term=science



PAGINA
http://www.librarything.com/blogs/librarything/2008/08/a-million-free-covers-from-librarything/