I'm using Cutline 3-Column Split 1.1 (but this question is good for any 3-column theme) and would like to be able to create posts/pages with either 2 sidebars and a regular-size content area, or 1 sidebar with an extra-wide content area. Can someone suggest a way to do this simply? In other words, I'd like to have two different templates and be able to choose which one to use for any post/page.