Turning the goban around during play. Is this allowed?

[Alguien]

and turning upside down is also useful when judging layout of text on a poster without being distracted by the content

In a position where you'll most certainly lose, turning the goban upside down could help.

Unless your opponent remembers the position and can set it up with the stones he recovers from the floor.

[Phelan]

There really isn't any reason sanrensei can't be on the top, unless that is another convention.

I've played sanrensei on the top when I played top right, and my opponent replied on my lower right. This was online, though, I've never seen it live.
Edit: Alguien: http://senseis.xmp.net/?NuclearTesuji
Btw, what happened to the Sensei's forum tags?

[Alberich]

Here's a related question...are you allowed to use either left or right hand when placing stones on the board depending on the situation? For example, placing a stone with your left hand and using the right hand to quickly touch the clock? In western chess this behavior is strictly prohibited. You have to use only one hand for both the move and the clock.

[Phelan]

I think most western go tournament rules say you have to hit the clock with the same hand you play. Not sure elsewhere.

[Bonobo]

Funny … I remember that when I regularly played Go with a friend in the end-80s we sometimes turned the board 90 degrees every dozen or so moves in order to train ourselves. Today I think it wouldn’t make a difference anymore.