If you are in the US, pick up your phone and dial 888-937-4462, enter an ISBN or UPC code, and Ringfo will tell you all about the product. If you need an example ISBN, try "1-4116-2551-X" (use the # key to represent the X).
To make it even cooler, Ringfo creates a product list associated with each incoming phone number. If you use Ringo while you are on the road, you can easily retrieve the list of items that you entered.
This is an example of a Voice XML application.
What will they think of next?