This is an example of a two-column layout with a sticky footer on Paul O'Brien's site:

Currently the two columns on the page (div#left and div#centre-content) take up 100% of the available width.
Would it be possible to wrap these columns in a containing div, give this new div a width of, for example, 960px and center it?

I've been trying to do this all afternoon, but everything I tried just broke the layout.
Grateful for any help.

By way of illustration I have attached two images.