Amaplug v188.8.131.52 is a great WordPress plugin whitch lets you easily and flexibly embed Amazon products in your posts, pages or widgets. It use the official Amazon Product Advertising API and you make money with every sale that comes about your site. The usage is very simply.
Amazon Bestseller v3.1.1 for WordPress uses the Amazon Product Advertising API and displays a bestseller list on your WordPress posts and pages. The lists will be refreshed and generated automatically. When using the [amazon] shortcode you specify the output by using keywords or the official browse node ids.