How far apart do you position your speakers ?

1.5 to 2 times the height of the speaker is probably just a coincidence because many floorstanders are in the 3 - 4' height range, which would put them 4.5 - 8' apart. That's about the distance of an EQ triangle in many small to medium rooms.
Get a pair of Maggies or Logans in there and it doesn't work.
I usually move them into the room to where the bass and midrange sounds good, then move them apart until the center image begins to get thin and diffuse, then move closer. This is usually pretty close to an EQ triangle but a little wider apart.

Wolf - Speakers will play music and can be enjoyed no matter how you set them up. If you pay attention to the details, they play much better.

Here's my formula, try it if you get curious or bored:

Speakers 1/3 into the room
Chair against the back wall (make sure the wall behind you is not hard/bare)
Speakers spread 83% of the distance from your ear to the plane of the speakers directly in front of you
Toe in to taste, I suppose this will have a lot to do with speaker design

My room is 13' front to back, 12' side to side.
My speakers are a little over 4' into the room and are about 68" apart center of driver to center of driver.

I went to a shop in another city a while ago and the owner suggested the 1/3 into the room and chair against the back wall. It went against what I believed, but I got curious and bored at the same time so I tried it.
I got the 83% thing from this thread and it actually worked pretty darn well.
It may be that my room is small, a cube, or whatever but this is where I have my speakers.

I did the plane of the speaker to the ear, but I believe the 83% mentioned in this thread was from ear to speaker.
The way I did it worked well for me. I have my rack on the side wall, so moving speakers farther apart would have meant closer to the gear.