I am always up for some fun science and this video is a great find from BoingBoing.net.
I wish there was a little more science talk about the chemical reactions taking place in the video. She gives all the ingredients ( Sodium Hydroxide (NaOH), Glucose (C6H12O6) and water (H20) ) and the change between yellow and red seems to have a direct relation to the amount of oxygen in the solution, shown by the color change when pouring or introducing oxygen.
I guess one use of this chemical reaction could be an oxygen level indicator, but for now it is also just plain cool. (LAUGH)