Research In Motion's BlackBerry Curve was the top-selling smartphone in the fourth quarter, according to research firm IDC, beating out Apple's iPhone 3GS. Although the Curve comes in multiple forms on numerous carriers, the result is still impressive considering that Apple's iPhone sales grew 100 percent in its most recent quarter, to 8.7 million, compared with the year-ago quarter. According to IDC, the Motorola Droid was the No. 3 smartphone in the quarter, benefiting from a full-throated marketing campaign by Verizon Wireless. What other smartphones rounded out the top 10? Special feature