Quick take on Action Engine, whose product got blurbed on the news wires today: They make software to translate web-based interaction, especially transactions, to handheld and portable form factors. And they're screwed. Because, useful as this stuff might be right now, the reality is that creating a shopping process that users might want to do on a handheld is a responsibility of the retailers. And it's better that they do handle it on the server end.
The transformations needed to make the few pieces of data that are really critical in a purchase presentable on a handheld are a natural fit for a server that has the context and intelligence to properly handle those pieces. Only the server, and the team of humans who are programming it, has the knowledge to decide which pieces of data are useful, and it doesn't make sense to have software try to figure that out on the client side. Especially when that software is running on a client with limited resources, like a handheld.