There is a rather more dramatic test than the one outlined above for people prepared to put their lives on the line: use a machine which kills them if a random quantum decay happens. If MWI is true, they will still be alive in the world where the decay didn't happen and would feel no interruption in their stream of consciousness. By repeating this process a number of times, their continued consciousness would be arbitrarily unlikely unless MWI was true, when they would be alive in all the worlds where the random decay was on their side. From their viewpoint they would be immune to this death process. Clearly, if MWI does not hold, they would be dead in the one world. Other people would generally just see them die and would not be able to benefit from the result of this experiment.
So it seems that the MWI assumes that all possible realities exist simultaneously? If this is true, then trying to commit suicide would make logical sense. You can do crazy stunts and not die, and if you don't die, you'd become famous.
What I meant by variations only specific to you would be like The Truman Show, where everything is staged for the main character. This would mean that you only think everything else exists, but it's really only you that exists, and with many worlds there would be different realities you experienced. In that way, you couldn't die because you are the only one doing the observing.
There is a flaw with that wikipedia example (which is based on Schrodinger's cat): the next time you walk into the machine the decay event is different. You could only walk through and find your fate a maximum of one time, win or lose, as the next attempt, if you were around, would be a different decay event.
This is from wikipedia: http://en.wikipedia.org/wiki/Many-worlds_interpretation
There is a rather more dramatic test than the one outlined above for people prepared to put their lives on the line: use a machine which kills them if a random quantum decay happens. If MWI is true, they will still be alive in the world where the decay didn't happen and would feel no interruption in their stream of consciousness. By repeating this process a number of times, their continued consciousness would be arbitrarily unlikely unless MWI was true, when they would be alive in all the worlds where the random decay was on their side. From their viewpoint they would be immune to this death process. Clearly, if MWI does not hold, they would be dead in the one world. Other people would generally just see them die and would not be able to benefit from the result of this experiment.
So it seems that the MWI assumes that all possible realities exist simultaneously? If this is true, then trying to commit suicide would make logical sense. You can do crazy stunts and not die, and if you don't die, you'd become famous.