I had read this some time ago. It was on my list of things to do to find it and post it here - The vision is great, and I think it will become reality very soon:
http://battellemedia.com/archives/001023.php
Currently Frucall does the price comparison, but there is no local information involved. Once we add the local information to our mashup, then we will be very close to this John Battelle episode!
--Nasser
Posted by nasser at March 9, 2006 10:29 PM