NBA executives were given the green light to begin discussions with player agents yesterday and also open up their practice facilities today, according to multiple sources.  A league memo was sent to all 30 teams Tuesday evening outlining the conditions.  Teams will be allowed to discuss financial terms with agents for unsigned rookies and free agents, but can't consummate any deals until the league opens for business, something that is expected on December 9th.  Meanwhile, players will be permitted to access team facilities and work on voluntary conditioning or strength training, but will not be able to work on "basketball-related activity" until the new collective bargaining agreement is officially ratified.  Also, the "New York Times" is reporting that the NBA will kick off its lockout-delayed season on Christmas Day with five games on three different networks.