One time my daughter and I were in the local grocery store and she wanted to play that game where you use the claw to pick up stuffed animals. Somehow, the stars aligned and I ended up winning two stuffed animals for her and now she thinks I can win at will, which isn't accurate at all. Some geeks have developed an interesting new robot for a project in college that reminds me of that game machine at the store.
The bot is controlled by the user's gestures using a hacked Kinect controller and turned into robotic movement of the Arduino controlled claw. The claw uses servos to move it around. I really like the part of the video where the dude tries to lean forward and move the box he is attempting to pick up and the claw jumps at his face.
The Kinect device is used to gather positional data from the user that allows the control of the claw and position of the claw within the range of motion. The thing needs some tweaking, but it’s a very interesting project and might be good for practicing for those claw grab machines at the store.