Version 2.0 [iTunes link], which appeared in the App Store Friday, allows users to buy and sell on eBay's flagship auction site, as well as scan product barcodes for comparison shopping. Previously, the latter two capabilities were available only in independent apps, eBay selling [iTunes link] and RedLaser [iTunes link], the latter of which was acquired in June.
Now users can do everything on their iPhones that they could previously do on eBay.com -- and then some. The integration of RedLaser's barcode scanning technology is particularly useful, allowing users to quickly compare eBay's prices to retail, and to pre-populate information about the items they're selling (which, admittedly, will only be useful for those few goods that still have their barcodes intact).
For a more comprehensive overview of the new features, check out the video below.