It's not going to guarantee you an A+ like showing up with a working portal gun would. But you can still wow your teachers by building your own version of Portal 2's potato-powered AI, even though the kit's a fraud.
With the included metal pins, alligator clips, and wiring, it looks like this sass-talking portable version of GLaDOS is actually powered by the potato it's wired to—but it's not. A single potato battery simply doesn't provide that much juice, so this £20 science experiment is instead powered by an included cell battery.
Disappointing, I know, but your teachers never have to know that. Nor do they have to know that the science fair poster detailing all of your research and hard work was actually included with the kit and created by Valve's writing team. First the cake, and now this. When will the lies stop Valve? [ThinkGeek via Red Ferret]