The advent of Web 2.0 and the spread of social software tools have created new and exciting opportunities for designers of digitally-mediated education programs for adults. Whether working in fully online, blended, or face-to-face learning contexts, instructors may now access technologies that allow students and faculty to engage in cooperative and collaborative learning despite being separated in space and time. By supporting the use of interactive methods and multi-media materials, social software offers educators more ways to engage learners than any preceding educational technology. Social software also empowers curriculum designers to more effectively accommodate many of the core principles of adult learning than was possible with earlier e-learning technologies. This article offers a basic introduction to some new possibilities in the design and delivery of digitally-mediated education, and an overview of the compatibility between the capabilities of social software and the principles of adult education. Digitally Mediated Learning Self-directed learning is largely unconstrained in terms of time and location and has traditionally been a primary affordance of distance education (Holmberg, 1995). From its inception, distance education has been marketed as a solution for adults whose occupational, social, and/or family commitments limit their ability to pursue educational goals (Holmberg). In the decades since the 1970s, demand for distance programs has increased as the globalization of national economies creates a competitive atmosphere that drives people to become life-long learners in order to be successful in the workplace (Merriam, Caffarclla, & Baumgartner, 2007). For many people, the term distance education now conjures up images of computers, the Internet, and online learning. In fact, with advances in mobile technology, the delineation between computers and various other electronic devices (e.g. mobile phones, music players, personal digital assistants, digital tablets) is blurring, and what was once termed e-learning or computer-mediated learning has become more commonly referred to as digitally mediated-learning (DML). This term implies that a medium for learning is provided by digital technology of some sort, and that interaction between participants and between participants and learning materials is not direct but rather carried out through the technology (Grudin, 2000). The use of networked devices, local networks, and the Internet is a key facet of DML, and online networked technologies are the delivery systems of choice for distance education offerings (Allen & Seaman, 2006). The accessibility and convenience of online DML is positioning the online environment as the primary context for adult/post-secondary education and training in general (Alien & Seaman, 2007; Kim & Bonk, 2006; McLoughlin & Lee, 2007). A Sloan Foundation study of more than 2,500 colleges and universities found online enrollments growing substantially faster than overall higher education enrollment, and the 17% growth rate in online enrollments far exceeds the 1.2% growth rate in the overall higher education population (Allen & Seaman, 2010). Allen and Seaman classified an online course as one in which more than 80% of content is delivered online and reported that over 4.6 million students were taking such courses during the fall 2008 term. There has also been a trend toward the use of blended learning or approaches that combine online and face-to-face delivery modes. As part of efforts to enrich students' learning experience, maximize efficiencies in time and facilities use, and enhance program marketability, many institutions are increasing their offerings of blended courses (Mossavar-Rahmani & Larson-Daugherty, 2007). This method is becoming increasingly common in K-12, higher education, corporate, healthcare, and governmental training settings (Allen, Seaman, & Garrett, 2007; Bonk, Kim, & Zeng, 2005; Watson, 2008). …