I came across the dry-ice bombs serendipitously. We had some dry ice for halloween left over, and when I was sitting around with some friends we had a water bottle. So we filled the bottle up with dry ice and added some water and we we making it jet the CO2 everywhere, puffingin it and being stupid (this was way back when we were in 6th grade). SO for some reason I decided to put the cap on, suddendly the bottle expanded (now mind you unlike these guys I had the bottle mostly full of dry ice). We knew something was bad so we tossed it in the kitchen sink (luckily a solid metal one), and took cover behind a wall. THe explosion was heard outside, though we couldn't hear anything for about 20-30 seconds. I remeber my dad coming in yelling at me and in the typical war scene all I hear is ringning in my ears and suddnely in a reverse fade the words he was saying. Later we learned of the full potential, which was also fun, but the greatest is that down in south-texas the grocery stores sell dry ice, and not expensive either.