RIDING ON CHROME: When the Google Chromebook first hit our radar, it was a clunky, nameless, unbranded CR-48 being used to access Khan Academy at a blended learning project in Oakland. Fast forward 16 months, and the Samsung Chromebook is #1 on Amazon's best-selling laptop computers. At the time of this writing, three of the Google Chrome OS devices have cracked the Top 20: the Samsung WiFi version at #1, Samsung 3G version at #13, and an Acer C7 version at spot #16. Mac and PC-powered laptops still dominate the list but the folks in Redmond and Cupertino are surely wondering where their big-money Madison Ave marketing campaigns dropped the ball during the holiday season.