I recently bought a Rattleback from ebay. For those who don't know what it is, it is simply a plastic (in my case) semi-ellipsoidal body, which spun in one direction moves freely but when spun in the other direction there appears a resistance which spins back the body in the other direction (You have atached a link to a video I made, to see more clearly what I am talking about).
I am from the Northern Hemisphere and in my case if I move it clockwise It moves with no restriction other than friction of the air and the table on which is siting. If I move it anti-clockwise it encounters resistance (apparently other than friction of the air and the table on which is siting) and is pushes back to clockwise movement.
The reason I made this post is because I am looking for someone from the Southern Hemisphere (I am thinking here of Chris, if I am right you said once you are from Australia), to try this experiment and post the result with a video as I did. I can transfer money to the one who meets this criteria and whises to buy one. One piece is 0.74USD (shipping included worldwide), not that expensive I would say. Here is the link from which I bought it:
Thank you and I await a response from someone willing to try this.