We just stopped by TechnoSource's booth at the Toy Fair to check out its just-announced Rubik's TouchCube , a fully touch-sensitive update on the old classic Rubik's Cube. The new model boasts a few features the old one did not (besides the lights and touchscreen), namely undo and hint options if you get stumped. Each of its six sides are touch-sensitive, and the cube's got an internal accelerometer so that it only recognizes the touching going on on the top side of the cube. It also remembers your place even if you turn it off -- great for those of us who will likely spend years trying to solve it just once. The Rubik's TouchCube is going to hit shelves this fall for $149.99. Check the gallery and video demo after the break