We recently gave our users the ability to add the power of Google Books to their sites. By adding a small code snippet to your website you can allow your users to search for books of every type and genre directly from your website. Best of all, it's easy, accurate, and free for everyone.
To add the Google Books box to your site, visit this page and follow the steps listed there.
The search box is currently only available in US English. We look forward to offering it in additional languages in the near future.