LittleBits Avengers Hero Inventor Kit ($149.99) Like last year's incredible Droid Inventor Kit that let kids create their own R2D2, this year's premier set from LittleBits is movie inspired: Now kids can make their own prototypes of Iron Man's iconic arm, specifically the energy device in the palm of his hand. Using the LittleBits safe, magnetically connected circuit blocks, the device gets different pulsing lights that operate with a flex of the hand. When kids are wearing their creations, they can store them on a provided mannequin arm that looks like it came off the Iron Man suit. The on-line instructions really set this kit off from other company's electric sets: They are clear, animated, and fun to work through. My only real concern is that like other LittleBit sets, this one is expensive for what appears to be relatively few parts inside. On the other hand, there are several construction projects here, plus the set has a "costume" value and may lead to creative, superhero inspired play that emphasizes engineering and tech over pure brawn.