The Biggest Lego Tower in the World?

Several times since my toddler discovered Duplo, we have built a single block tower as high as we could reach. At a certain point it becomes unstable and topples over. The people at Open University in the UK have taken our quest one step further, to discover how high a Lego tower can be before it crushes the blocks in the first layer, theoretically, of course. Taking into account the mass of the material and its yield strength, they believe the tower could stretch 2.17 miles. Though at this height the strength of the blocks would not be the biggest obstacle; the tower would encounter the same problem that my toddler encounters with his Duplo -- it would topple. So physicists and pre-schoolers, all building towers out of toy bricks to watch them fall, that's what I want to be when I grow up!