Sprint has been teasing for weeks that its LTE network would soon launch in Los Angeles. If a fresh leak from Phone Arena proves true, we may at last be down to the final hours before the Now Network officially flicks the switch for those Angelenos -- and a good chunk of the US population, for that matter. The staff memo reportedly has LTE formally launching in 21 markets on April 12th, with LA being joined by larger cities across the US like Charlotte, Memphis, Norfolk, Virginia Beach and Newport News. Its schedul