It is almost certainly not due to Earth-spin. It is mostly hormonal factors that make one side of the shoot grow faster than the other that enable the shoots to spiral.

Water doesn't always go clockwise, and it doesn't have to go anti clockwise in Australia. Some people say its the Coriolis effect that means it doesn't matter where you are in the world, but others deny that.

http://www.bbc.co.uk/bang/handson/plugholes.shtml

and Coriolis effect here

http://www.abc.net.au/science/louts/coriolis.htm

As for runner beans climbing anti clockwise, here are two contradicting references:

http://allotmentblog.dailymail.co.uk/2011/06/why-do-runner-beans-spiral-clockwise.html

and one saying they grow anti clockwise from this site

http://www.growsonyou.com/question/show/162021.

Given there seems to be some argument about whether beans grow clockwise or anti clockwise in Britain, I'm willing to bet that Australian bean growers also have the same argument...

I have read the suggested pages with interest,
I guess there is no definitive answer, like most subjects there is always contradictory evidence.
"The exception proves the rule" comes to mind, but that's a different subject ! ! !
thanks for helping me try to understand, but probably more confused now than ever. :)

bazza

just had a thought, ouch ! ! ! !
perhaps it's because you see things upside down in Australia, it appears to be the opposite way round,
he! he! he!

Well, upside down or not, you can be sure that when water goes down the plughole in Australia, it won't look much different from when it goes down the plughole here!