Choosing a smartphone? Consider the OS Summary: If your phone contract is about to expire, there's a very good chance that the next phone you get will be an all-singing, all-dancing smartphone. But which operating system should you go for? By Ben Woods | December 23, 2011 -- 12:25 GMT (04:25 PST) Follow @BenWoodsZD Topics: Mobility, Smartphones Kick off your day with ZDNet's daily email newsletter. It's the freshest tech news and opinion, served hot. Get it.