Exloding Hot Water Heater

the other day here in Phoenix somebody had thier hot water heater explode and turn into a large rocket ...here is the story and a web site where some guys did this in a controlled enviorment...I wouldnt mind doing this but hot water heaters can be expensive......

story......http://www.eastvalleytribune.com/story/123110

experiment web site......http://www.waterheaterblast.com/