Spinning balloons are the springboard for various types of video stabilization projects.
Mike Manes, W5VSI, has built this test bed. Essentially, the system consists of a means of sensing the orientation of the payload via magnetic sensing. A servo can then adjust the pointing angle of the camera to compensate for these movements.
The dome containing the down pointing camera. The camera pointing assembly can rotate freely 360 degrees in the horizontal axis. The camera also has a vertical servo which can point the camera anywhere from towards the horizon to straight down.
Slip ring electrical contact to connect the camera and servos to the controller package. Slip rings are necessary to give free motion to the camera negating any wiring harness tangling issues.
Installed into a payload enclosure, sorry about the messy background.