This is how I did it:

Layout the page normally using text boxes, photos, shapes etc.

Once you get everything how you like it, go back and right click on each
item (object) and go to the Format Object box.  Pick the "Layout" tab in the
box.  Then set the Horizontal postition from "Top Left Corner" to "Center."  

I am no expert, but I assume the Horizontal Pixels are split according to
the document size, so it may ne be a perfect solution (I used a 760 X 4600
size, and it worked ok on my widescreen monitor).

I don't know if this will work for all situations, but it helped me out and
I wanted to share it.  I hope it helps somebody!!!

Rich
rda889@sc.rr.com