Open Interface has created a nifty LEGO car that is controlled via Bluetooth mouse using their patented "BLUEmagic Host Application Programming Interface".
A Bluetooth mouse controls the direction of a Lego car. Move the mouse forward and the car moves forward. Move the mouse backward and the car moves backward. Move the mouse left or right and the car turns left or right.
Henry Lim struck out to design and build what could arguably deemed the pinnacle of Lego structure—a working Harpsichord. With the exception of its wire strings, the Harpsi is built entirely out of Lego. The 100,000 piece instrument would likely have one of the largest manuals of tiny, annoyingly difficult-to-understand isometric diagrams to date, but the project page does a rather good job of explaining the process he undertook to build such a thing. It also features an MP3 of the harpsichord in action. Project Page
LEGO Pinball Machine
Gerrit Bronsveld & Martijn Boogaarts from The Netherlands created this Lego Pinball machine. Obviously, the ball itself couldn't be made from lego blocks and a regular 1 1/16" steel pinball was just too heavy for the Lego motors, so a 1" glass ball was used as the main playing ball and a regular steel ball was used for the tilt mechanism. But the rest of the game is 99.99% pure Lego.
But don't think Lego is just coloured plastic blocks because it's developed into far more that that, with motors, sensors, controller boards and its own programming language. All this along with over 20,000 Lego blocks went into making a fully functional pinball game with true coin operation, three flippers, ramps, specials and extra balls.
LEGO Difference Engine
Nineteenth-century computer pioneer Charles Babbage is taken back—via Lego. Andy Carroll, an apparently highly-skilled Lego builder and mathematician, created this functional mechanical computer, modeled after Charles Babbage s Difference Engine, which was a precursor to modern-day computers.
Amazingly enough, this machine is able to solve mathematical problems known as second- and third-order polynomials, and is able to calculate those to three or four digits.
LEGO Lie Detector
You can't get more simple than the Galvanic Skin Response GSR sensor. It is just a cut 9V LEGO motor wire and some aluminum foil wrapped around your fingers with tape. It was inspired by talks by Mindfest panelists Karen Wilkinson and Mike Petrich who talked about using this type of sensor.
It is popularly known as a lie detector, but is also used in Biofeedback conditioning. The theory is that; the more relaxed you are the dryer your skin is and so the higher the skin's electrical resistance. When you are under stress your hand sweats and then the resistance goes down. The range is reported to be 5K to 25K Ohms. 5K would relate to a RAW reading of about 340, while 25K should be around 730. Read more
Winston proves that you don't need to spend a fortune to get a cool looking computer. This unique system boasts a case that's made entirely of Legos, VIA C3 933MHz processor, 8X DVD drive, 256MB Kingston PC2700 DDR SDRAM, 70watt Micro-ATX power supply, and an IBM 18GB hard drive.
A wireless keyboard and mouse provide mobility. Though not the most powerful system, its more than enough for surfing the web, talking on Skype, or just watching movies. See the step-by-step tutorial at http://home.hawaii.rr.com/chowfamily/lego/
LEGO Air Conditioner
At the 2006 Carrier Convention, a functioning replica of Carrier's newest air conditioner was shown, complete with the compressor, valves and working fan. It took every hour of both days of the convention, but the result was impressive. And with that spinning fan, wow, what a breeze!
LEGO Vending Machine
Created by Anders, this fully-functional LEGO vending machine consists of four light sensors, four touch sensors, four motors, and two RCX's. It even has a coin-slot with the total amount being shown on an LCD display.
LEGO CD Thrower
The "Hammerhead" —a Philo creation— can eject a CD disc at high speed, literally causing it to break on impact. This Lego device consists of "two main parts, the head that throws discs, and the tail which feeds the head with compact discs."