Amazon is using a Flex application on at least two pages related to its Amazon Unbox service. There's a Flex application on the main Unbox page that allows visitors to browse and view previews of available videos.

A similar Flex application is also being used on the free Unbox downloads page, where visitors can browse videos that are available for free.
It looks like the same application with different data is being used on both pages. Its great to be able to browse the videos and watch the previews from within the application, without having to launch another plugin or external video player.
Comments
Flex vs Flash
Is there any way to determine whether a particular SWF file was compiled using Flex versus Flash or for that matter any other complier. I agree BTW that this is almost assuredly a Flex app, however since the same thing could conceivably be created using Flash I'm just wondering if there is a way to tell for sure.
Re: Flex vs Flash
There might be some file level way to tell such as some sort of versioning or signature. Otherwise, they compile to the same file format. It might also be possible if the swf obviously uses certain component features that would identify a component. Some components are available in Flex and not Flash.
James Ward has created an
James Ward has created an online script that checks a SWF file to see if it was made with the Flex framework:
http://www.jamesward.org/is_it_flex/
Mike