These mosaics are 30" square and use about 9,000 elements each. They were constructed by teams of my students which saved my thumb a lot of wear-and-tear. :) Come see a lot more at WWW.BRICKITGOOD.COM.
I think Lego is such a great learning tool. It really gets the brain working in ways that books or other forms of learning can't (I'm not knocking books). Books are great for one type of learning, Legos are great for another type.
I couldn't help but notice the method your students are using. It appears they're looking at a color printout but converting it to a grayscale mosaic. I was wondering if you could say a few words about the process.
Keep up the great work.