I use a layout with columns. However these cause problems when the theme switches to mobile view. I have tried a variety of column systems but none work.
The demo site over at http://twentytwelvedemo.wordpress.com/ appears to have a 2 column layout on the front page which does respond correctly when viewed on a mobile device (or just shrinking the browser window). Is this a specific column plug-in to use with this theme or is there another way to achieve this effect?