I am using the accelerometer (MPU6050) for tracking the orientation of the base of the platform. As I tilt the base, the accelerometer tells the angle of the tilt. According to that angle I send signal to the servo motor to rotate the platform so that it remain horizontal to the ground.
Side View, wound around the servo wires on metal or ferrite ring (if not mistaken) so that when two separated signal send to two wires, and when the servos are drawing current from Arduino, it wont affect much.
Very simple right?! This is a demo video of an simple Arduino Balancing Platform.
You can get the code with required library here: https://drive.google.com/file/d/0BwL1jFbR4_TtcmhtX3l4RmNHUEU/view?usp=sharing