It’s a bit random, but this YouTube video of a DIY Lego printer was recommended to me by a friend. (Thanks, Lorrie!) It’s not directly related to ESL, but it would probably give your students something to talk about. I’ve always enjoyed seeing projects like this ever since building a $50 Interactive Whiteboard. With the rise of Instructables.com and other open source and DIY sites, it’s amazing what people are able to build for themselves. Having a team of Lego people “controlling” the printer is a really nice touch.