Wired reports that at Wake Forest University, professors are using PDAs to quiz students to make sure they understand the principles in the lecture. The idea is, quieter students who don't want to admit out loud that they don't understand would feel more comfortable communicating it this way. I can't help but wonder, though, maybe if the class were discussion-based, there wouldn't be such a need for this. Cynthia Selfe and Gail Hawisher, in one article, said that sometimes computer technology supports some of the most "lockstep" teaching they'd ever seen. I think this is an example.