LightSquared scored its second big win in as many days as Best Buy said it will use the 4G network to expand its Best Buy Connect service. The news comes on the heels of yesterday’s agreement with Leap Wireless, and securing such a high-profile brand should provide some assurance to LightSquared investors who have been getting nervous. As El Reg wryly noted, “The upstart operator still has a lot to prove, but at least now it has someone to prove it to.”