Here is the digital designer file (includes building instructions) for the LEGO NXT Hand Puppet shell.  It fits under an 8-inch Toys R Us Animal Puppet.

This example has a Jetman-esque game that shows up on the NXT screen.  It uses a circle as the player's character and rectangles for obstacles.

This example shows how to turn a user input into a corresponding sequence of sounds.  Each letter in the alphabet has its own case structure with morse code sounds.  The front panel input is converted into a usable form (lowercase) and then parsed through one letter at a time.

This is an example to turn your NXT into an Etch-A-Sketch. This program is meant to go with an NXT with two motors and two buttons attached.  It works nicely if wheels are attached to the motors to act as controls for the game.

This project uses the ultrasonic sensor, shift registers, and some calculations to determine the velocity of an object moving towards or away from it.