Johnny Boy:
I saw your question in the equipment section on water flowing the other way in toilets in Australia, and I wanted to give you a serious answer (I am a sometimes physics geek), but didn't want to stomp on Thomas' awesome thread. What you are intimating is called the Coriolis effect, and it does rotate a vortex in opposite directions depending on what hemisphere you are in. However, the Coriolis forces are very weak, and can easily be overcome by lots of other things in a system like a toilet. The vortex created in your toilet is generally created by the shape of the bowl, and the angle of the flow of water when you flush, so if I took the toilet out of my house, flew to Australia with it and installed it in Grant's bathroom, I am darn sure the swirl would go the same way it did at my house. But if you have a large tank of stationary water, and started to drain it from the bottom, often a very small vortex will form on its own, this vortex would spin in opposite directions at my house than it would at Grant's.
Hope this helps.
Mick
I saw your question in the equipment section on water flowing the other way in toilets in Australia, and I wanted to give you a serious answer (I am a sometimes physics geek), but didn't want to stomp on Thomas' awesome thread. What you are intimating is called the Coriolis effect, and it does rotate a vortex in opposite directions depending on what hemisphere you are in. However, the Coriolis forces are very weak, and can easily be overcome by lots of other things in a system like a toilet. The vortex created in your toilet is generally created by the shape of the bowl, and the angle of the flow of water when you flush, so if I took the toilet out of my house, flew to Australia with it and installed it in Grant's bathroom, I am darn sure the swirl would go the same way it did at my house. But if you have a large tank of stationary water, and started to drain it from the bottom, often a very small vortex will form on its own, this vortex would spin in opposite directions at my house than it would at Grant's.
Hope this helps.
Mick
Mama Mama many worlds I've come since I first left home.
It is funny the things that get us all thinking. I was assuming that the direction the water "jet" is shooting is gonna cause a swirl in one direction, which ever hemisphere you are in, so maybe the toilet would be a bad example of that physical phenomenon. Thanks, I now don't have to ask such a question and make a fool of myself again..... As I remember from science fairs some kid took two bottles and taped them together at the openings and filled them with colored water, much like an hour glass. when tipped over a "Tornado vortex" was produced to study the rotation. That would be the best way to test that theory I guess.... 
