Use of laptops and similar devices is not permitted in my classes. I have two reasons for this: (1) They are a distraction, and (2) there is evidence that students learn more when they take notes by hand. Here are some links providing evidence that we learn better if we take notes by hand, rather than on our laptops:

From the journal, Psychological Science, an article by Pam Mueller and David Oppenheimer reporting their original research.

These three articles report the on the Mueller/Oppenheimer study:

Additional sources:

A related point: There is reason to think we absorb less when reading from a Kindle rather than paper, from The Guardian