Think back 20 years, Edutopia reports. Pay phones still worked, and only doctors carried pagers. Laptops weighed as much as bowling balls, and few of us had Internet access. In fact, much of what we now consider commonplace — Google, email, WiFi, texting — was not even possible. If that was 20 years ago, where are we going in the next 20? We are all going mobile! Tablets, smartphones, Chromebooks — and yet, these devices only serve as the most recent iteration of mobile technology in the classroom. Remember Netbooks? How about those old-school Macbooks that looked like toilet seat covers? What if we go back further? What about chalk and slate?