I based my robot on vahid_you2004's instructable (Balancing Robot).
But decided to show you some pictures and video's i took of my robot...If you want to make it and need a more detailed description of how to make it check out the Balancing Robot instructable.
Hope you enjoy :D
***What you'll need***
-Gears-salvaged mine from a toy car
-Wheels and shaft to attach them to
-AA battery holder
-SPDT switch(with a metal lever), couldn't buy one anywhere close to where I live so I had to improvise
-small nail(used to hold gear in the gearbox arrangement)
-4 AA batteries(I recommend rechargeable ones)
-rectangular plastic or metal piece(to mount battery holders onto.)
**tools you'll need**
-hot glue gun
-lighter(to shrink the heatshrink tubing)