The human race is a creative bunch, I mean, there's someone out there who developed a tea bag out metal so you can use leaf tea without a strainer. Sometimes all it needs is the right spark for an idea to form, in this case the spark was C4 and a desire to break the laws of physics. Watch these guys make a tank fly in Battlefield 3.
I hope that someone in one of the world's militarys is looking at this and thinking, "Now that's a good use of our tanks. This war business is looking, frankly, a little dull in comparison."