One of the coolest projects I have done so-far with my kids is a "near-space" balloon. That's not quite into space itself (100Km+) but so high that the sky looks black and you can start to see the curvature of the earth below you. The Flickr set with the photos from our first launch is here: http://flic.kr/s/aHsjK22nDc This is a quick-fire slideshow of the photos from the balloon, formatted as a 2.5 frames/ ...