Despite their growing popularity, digital alternatives to conventional textbooks are stirring up controversy. With the introduction of tablet computers, and the growing trend toward "cloud computing" and "open source" software, the trend is accelerating because costs are coming down and free or inexpensive materials are becoming more available. Evidence is also starting to mount that this new technology can have a positive effect on student learning, although teachers will require training and professional development to integrate it effectively into their teaching. (Contains 18 online resources.)