Apple (NASDAQ:AAPL) climbed atop the U.S. handset heap in the fourth quarter of 2012, becoming the largest U.S. handset maker for the first time in a quarter, according to new data from Strategy Analytics. Apple passed Samsung Electronics to become No. 1 for the first time in the period by selling an estimated 17.7 iPhones in the U.S. in the quarter, according to the research firm, giving Apple 34 percent market share. Strategy Analytics said Samsung shipped 16.8 million mobile phones in the United States, for 32 percent share, during the fourth quarter. The firm also said LG Electronics remains the No. 3 player in the U.S. mobile phone market, with 4.7 million mobile phone sales in the quarter for a 9 percent share of the U.S. market, dipping from 6.9 million units and 14 percent share a year earlier. The stats on Apple and Samsung closely match those from the NPD Group, which gave Apple 39 percent of the U.S. market in the fourth quarter and Samsung 30 percent. However, NPD has had Apple in the top U.S. spot before, including in the fourth quarter of 2011. Post