We told the builder that we would put our toilet paper holders up, not wanting some random dude deciding the wheres and whats of our poop paper. The only downside is that now we have to decide (and live with the consequences).
According to e-How, the standard position is on a side wall 26 inches off the floor, 8 inches in front of the front of the toilet. They also offer advice on placing the holder on the rear wall (we ain't doing that...) or on the wall in front of the toilet (yoga, anyone?).
According to random commentators on the Bathroom Forum on Garden Web, distances of 6, 21, 24, 26, 24 to 30, 29, 30 inches off the floor have been used.
According to a dude at doityourself.com, the code says 26 inches from the floor, 8 to 12 inches forward of the front of the toilet.
Someone made the point of being careful not to locate it too close to the toilet lest an elderly person (or young drunk...) decides to use it as a prop to stand. Seems like good advice. We'll have to (ahem) practice this week to see where we think it should go.
And let's not get started on the orientation of the roll in the holder (although over is clearly correct!).