On Friday, we told you about 9 cities that had apparently started receiving T-Mobile's LTE signal. This was based on information received from OpenSignal, a crowdsourced Android app that announces where to find wireless coverage. T-Mobile is expected to officially launch its LTE service this coming Tuesday at a major event that should also include the introduction of the carrier's new pricing plans.On Saturday, a leaked internal document from T-Mobile revealed the first seven cities that will officially offer T-Mobile LTE starting on March 26th. The cities are Las Vegas, Nevada; ...