The sidebar won't collapse in Metafilter, whether you are logged in or not.
Sidebar collapse. I think when folks were asking for the sidebar collapse to be brought back, it was not so much to get rid of clutter as it was to free up that 25% of the screen that the front page posts could run into. Even with the sidebar collapsed [and the ads remaining, they're ok with me] I still have a large blue stripe down the right hand side, making it one longass page. Is there a way to wiggle around the front page elements to have the ad present but more side-to-side room for posts, or is this just me and my mac pissing into the wind?