Arduino R/C Lawnmower
This my friend is a really cool project. Controlling a lawn mower with a remote, making it do all the hard work while you enjoy a drink..now that is life 
. This guy really did put in an effort. Check the project out.
Soundie: a musical touch-sensitive light-up hoodie
Woah now this is a cool one . A hoodie for all the music lovers i must say. A simple way of amazing people with your jacket which lights up when you touch it. A really good use of Arduino. Check the Project out 
Link to the project: Click Here
Ardu-pong! the Arduino based pong console
Just like we brought you the project of a hangman game based on Arduino..here is another one . This time its ping pong. Although the project is not yet that much polished but this my friend is the most updated version of it.
P.S: The whole system is cleverly hidden in that black box. :p
Link to the project: Click here
Addressable Milk Bottles (LED Lighting + Arduino)
A nice way to use a useless object . By using LED and a Milk Bottle you will not only be having a decent way to light your room but will also be helping the environment by recycling stuff. Because LEDs are tiny, you can put them almost anywhere and they use only 3 watts of electricity which is very low..
Link to the project: Click Here
Iphone Controlled Arduino Tank
Something for Iphone and Arduino lovers .. A very interesting project which uses an Iphone to control an Arduino based tank. Who wouldnt want to play with one? ..It uses the Iphone to send signals to the tank with the on-screen controls being easy as 1 2 3 haha . Enjoy with the full source code given in the link below.
Link To The Project : Click Here