It very nearly caught up to Yahoo in the last round of ComScore figures, and Microsoft has now finally done it -- it can officially claim to be the number two search engine in the US. According to the research firm, Microsoft's Bing search engine and other websites fielded a total of 2.75 billion search requests in December of 2011, compared to 2.65 billion search requests handled by Yahoo -- that translates to a market share of 15.1 percent and 14.5 percent, respectively. As you'd expect, that still leaves Microsoft far behind Google, which processed a whopping 12 billion search requests during the month, representing