Human embryonic stem cells possess the unique ability to differentiate into any adult cell type. Recent advances in the understanding of stem cell biology make new applications possible for stem cell based technology. Of note, it is now possible to reprogram terminally differentiated human somatic cells into pluripotent cells that are functionally equivalent to embryonic stem cells. These induced pluripotent cells may become the substrate for future disease models and cell-based therapies. In addition, novel techniques for genetic manipulation have increased the ease with which genes can be modified into stem cells. In this review, we describe these novel technologies as well as developments in the understanding of basic biology of stem cell pluripotency and differentiation.