The term “blended learning” is being used with increased frequency in academic publications and conferences as well as in industry trade magazines around the world. In 2003, the American Society for Training and Development identified blended learning as one of the top ten emergent trends in the knowledge delivery industry (Rooney, 2003). In higher education, some predict a dramatic increase in the number of hybrid (i.e., blended) courses that will include as many as 80-90% of the range of higher education courses (Young, 2002). Additionally, in a recent Chronicle of Higher Education article, the president of Pennsylvania State University, Graham Spanier, was quoted as saying that the convergence between online and residential instruction was “the single-greatest unrecognized trend in higher education today” (Young, 2002). This article provides an overview of blended learning environments (BLEs) with examples from both corporate training and higher education contexts. It also identifies the most common benefits and challenges related to the use of blended learning environments from the research literature.