Compact Chimney Climber (CCC)

You must have already thought about robots with wheels, tracks, 2-legged, 4-legged, fixed in place while sorting balls, LEGO bricks, drawing... But have you ever imagined a robot which doesn't touch the ground? So it's right here. CCC is built with a single NXT 2.0 set, from the instructions (building & programming) from The LEGO Mindstorms NXT 2.0 Discovery Book. It stops when it reaches the top (ultrasonic sensor) and it has a balance sensor, assembled with the color sensor. Here's it in action:

Hybrid Brick Sorter

Here is the first post with one of my robots: the Hybrid Brick Sorter, a robot which sorts standard LEGO bricks by color (green, blue, yellow and red) and by size (2x2 and 2x4). Building and programming step-by-step instructions following "The LEGO Mindstorms NXT 2.0 Discovery Book", but the "V2" was programmed entirely by me, only based on the original program. Built with just one NXT 2.0 set. Watch this video for further information: