Also try "Compare Everywhere". I have all three installed and find that they compliment each other well...
Compare Everywhere and ShopSavvy use different databases, and sometimes one would have a product or a good local listing hit, but not the other, and vice versa.
As to Barcode Scanner - it is not as useful for search, as it simply redirects your barcode to the web browser, but it is great for other code scanning, like QR and DataMatrix 2D codes. It also integrates itself into contacts, so that when you open up a contact on your phone you can press menu and there's an option to generate the QR code on screen for another G1 (or similar) phone user to scan it off your screen, and viola - contact shared.
LEM.