How do you share the sweet spot?

I think the point is "you never have to share"
(it is in your head, isn't it?)

I always let guests sit in the hot seat. You can share the image by having seats in front and behind the hot seat which is bit odd in most rooms. 
I'm not sure but I think an ambiophonic system can image in different locations. It is definitely not for digital phobic audiophiles as a fair amount of DSP magic is required. 
I can put the sweet spot anywhere in the room and will put it at my desk in the far corner of the room when I am working. This is done by changing speaker delay and phase/time relationships. It is already programmed in. I just have to push a button.

Are you kidding?  No way!

Mapman, the same rules of acoustics apply also to Ohm speakers. If a speaker "images" in different locations at the same time it most likely has no image at all.
I went and reviewed the literature on Ambiophonic reproduction and it also requires the listener to be equidistant to both speakers. It also requires the frequency of both speakers to be exactly the same so room control is essential. I actually have ambiophonic programming in my Tact and I would love to try it but I can not get my speakers the requisite 30 degrees apart as my theater screen is between them and 60 degrees does not work at all. 

big greg, "no way" what??