Rumors have been flying for months that Microsoft might buy a cellphone firm, and now that the tech giant's smartphone platform, Windows Phone 7, has taken off, the possibility is generating more speculation than ever. Microsoft's ebullient CEO, Steve Ballmer, recently sidestepped questions from CNBC about the idea, but analysts say two companies ripe for acquisition are Blackberry maker Research in Motion (RIM) and Finnish cellphone giant Nokia. Should Microsoft shell out for either of them, or stick to what it knows best — designing and selling software? (Watch Steve Ballmer's CES address)

Buying Nokia would be a smart move: "Nokia should be the target," says Matt Rosoff in Business Insider. Not only is it "by far" the biggest phone maker in the world, but, with its smartphone business sputtering, it is also "more affordable than ever." Microsoft may hate hardware, but "selling mobile software is a crummy business." The alternative for both companies "is a slide towards irrelevance" in the biggest tech market since the PC.
"Now is the time for Microsoft to buy Nokia."

RIM is the best option: It "has been rumored forever" that Microsoft would buy RIM, says Shira Ovide in The Wall Street Journal. "That doesn't mean it isn't a good idea." Microsoft's Windows Phone 7 platform can't compete with the "big dogs in smart phones" — that is, the iPhone and Google's Android — and RIM won't overtake them, either. Together, they might stand a better chance.
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Microsoft is doing fine on its own: Microsoft's own smartphone platform hasn't had a "bad start," says Ed Hansberry in Information Week. Around 1.5 million devices running on Windows Phone 7 have been sold, and it is likely to overtake RIM this year in terms of the number of apps available. Microsoft won't "take over the market" any time soon — but it should "survive as the market weeds out some of the weaker platforms."
"2011 looks bright for Windows Phone 7"