Unintended Consequences. I haven't seen anyone do this, but one could, and it would be cool. I recently read an article about the Wish List feature on Amazon and other sites, and particularly that Wish List entries don't necessarily convert to sales.
Everyone in my family uses the Wish List (you can look up mine); it's a handy way to keep track of books (or other stuff) that are on your 'I want to read this some day' list. (The sick pop-psych angle is that the Wish List experience is so much like the 'One-Click-Shop' experience that you get the endorphin rush of buying the book without spending the money to buy it or the time to actually read it. But I digress.)
Anyway, getting back to my point. What would happen if one wrote an app combining Amazon's and Google's or some other 'Web Services API's? (Web Services APIs are faddish enough that if they don't have it, Amazon's competitors will soon have one. Also what about the various 'best price' sites like Price Scan?)
What if I could get a nice list showing each of the items on my Wish List including the top three web sites where I could buy the product at the best price? Anyone want to try to build that? Has anyone already done so?