Here is an NPR story of a professor's complaint about inappropriate use of laptops in class.
Once in awhile I'll ask people in a lab to quit typing while someone is giving a presentation (or while I'm lecturing). The clicking of the keyboard can be a distraction. Students sometimes say, I'm taking notes. But when I walk around, I see a lot of off-task behavior.
Laptops are just one of the personal technologies making their way into classrooms. Phones and iPods are two other examples.
What do you think? Seems that a best response is to develop some rules for appropriate use - but not to block these things out entirely. At least in most cases. I acknowledge that sometimes, you just gotta take them out entirely.