It's kind of a strange request, and I didn't think too much about it, and I'm hoping I don't have to -
I'm looking for a way to limit certain content from increasing the horizontal size of the page when it's wider than the window's size (no scrollbar for the window).
The catch is that the content, when clipped by overflow:hidden(or overflow-x:hidden) applied by a containing div, should be centered. Equal clipping on both sides should be done. For your information, margin:0 auto does not seem to work for this, in case someone was wondering.
A funny occurance though was when I tried margin:0 -25%. While I knew it would not be my solution, I thought I'd see what It'd do (perhaps the solution was related). You could try it yourself. It's interesting in that the object at first seems to get cut off equally on both ends, but after a certain point of decreasing window size, it slides back to the way it came!