This is a simple idea, but one which is probably quite hard to execute. Issues that spring to mind: identifying identical products (they may be named slightly d

This is a simple idea, but one which is probably quite hard to execute. Issues that spring to mind: identifying identical products (they may be named slightly differently, or be similar variations on a product - ipod w/ 8GB or 16 GB), web prices may often be different from in-store prices (e.g chains will price goods on a store-by-store basis), plus you got multiple prices for a product (big, small, 500ml, 250ml), old prices, new prices, discounted prices - and what about geographical location? Possibly hard to identify for some sites / merchants. Interesting, none-the-less.