Social networking sites are a popular way for physicians to communicate about clinical, professional, and social topics. These sites can be used for educational purposes, professional interaction, and for general discussion. There are many popular sites oriented toward health care professionals, each with their own functionality and style. We reviewed the top physician-oriented networking sites, as well as popular general social networking sites that can be used for physician communication. We also provide background on social media communication, as well as specific advice for online physician communication and a discussion of confidentiality.