In a joint announcement last week, Comcast and Skype unveiled plans to provide video chat service to Xfinity customers. By adding an adapter box to their set-top box and a "high-quality" video camera, subscribers will be able to send or receive instant messages or video calls to any Skype user worldwide, including smart phones, tablets, and personal computers, as well as other Comcast subscribers who are equipped for Skype calls. The...