This new article from IBM developerWorks seeks to show you how to create an interface with the Amazon web services - specifically the E-Commerce Service.

This is the first of a two-part tutorial that constructs an Amazon storefront using PHP and the Amazon E-Commerce Service (ECS). The storefront constructed will allow shoppers to view items displayed in lists or search for specific items in the store. Part 2 will cover the shopping cart, recommendation service, and constructing a collectibles shop.

You'll need to register to get into the tutorial, but it's a good, full tutorial (12 pages) that walk you through step-by-step on how to set it all up. They detail interaction with the Amazon interface as well as show you how to send/recieve SOAP requests. From there, it's really just a matter of pulling that data into variables where it can be used and creating a front-end for it...