What is this goo? blue goo? boo goo? goo goo?

Goo....... There is no other way to describe this. Maybe Blue Goo, or boo goo, or googoo... how about yukky goo? How do you spell "goo" anyways? (or 'yukky' for that matter?) My girls made this 'goo' at the art fair last weekend and I am constantly finding it laying around in it's 'protective plastic covering' (a ziploc). That's an understatement. Rather, the ziploc bag is protecting whatever it is resting on from the 'boo goo.' It's actually quite fascinating than disgusting. It's always cool to the touch and moist. It doesn't have a foul smell - but does crunch when you squeeze it. It's bizarre to say the least... {{{{big sigh}}}} the more fascinating, odd, and queer it is, the longer it holds my girls attention (as well as mine.....)