- The chan_skype module allows Asterisk to connect to Skype, enabling calls between Asterisk and Skype users with no special programming required. - This provides a practical gateway between Asterisk and Skype's large user base, removing the "ugly hack" factor and scaling appropriately for business use by connecting Asterisk and Skype users. - Use cases include business call centers using Skype minutes for low-cost PSTN integration, inter-office communications without routing costs, and consistent reachability for road warriors utilizing Skype minutes from any device.