Apple's Cook hints at prepaid iPhone; smartphones, tablets drive U.S. mobile data revenues to $55 billion in 2010;

> Apple's Cook hints at prepaid iPhone, shaking up handset distribution.

> Smartphones, tablets drive U.S. mobile data revenues to $55 billion in 2010.

> China Unicom takes on iOS, Android with Wophone mobile OS.

> Angry Birds descend on Windows Phone 7 this spring.

> Mobile gaming startup TinyCo raises $18 million in Series A.

And finally... Eight-year-old arrested. For the fifth time.