Hi Nancy: You've described a great example for filling time that productive and related to the topic. In this case it involves computers. But every back up plan (even those without the need for computers) should serve a similar pupose. A good back up plan should be something that can be initiated on realtively short notice, is pertinent to the lesson, requires little preparation, and provides students with the feeling their time is not being wasted. I think your example fills the bill! Regards, Barry