Engadget - There are certain back to school purchases we could never talk you out of. A laptop? Vital. A smartphone? Highly recommended. A printer? Necessary -- if you're the kind of person who finishes papers minutes with minutes to spare, leaving no time to swing by the computer lab on the way to class. But a tablet? We'll be honest: we can't think of a good reason why you need one, but we can more than sympathize if you're dead-set.