San Diego-based Active.com, the online site geared towards the sports enthusiast community run by Active Network, reported this morning that it has added Sony Electronics as a client. Active.com said that it has been selected by Sony Electronics to lead an online and offline marketing campaign around Sony's new Walkman MP3 player. Financial details of the win were not disclosed. The deal includes launching a new, Sony Walkman online community for runners, plus the creation of "Team Sony", a group of 120 amateur athletes who will represent the Sony Walkman brand as ambassadors.