Firefox/Chrome/Safari: If Facebook's a little too cluttered for your taste, the Minimalist Facebook extension/Greasemonkey script can tidy things up. After a quick install, a visit to Facebook will be focused solely on the content you've chosen to view.
Facebook's interface has always managed to confuse me. I'm sometimes unsure of where to click because there are multiple links and headers that all appear to go to the same place. After installing Minimalist Facebook I was happy to find that pretty much all of those distractions are gone and I concentrate on just the page content and the main navigation.
There's really not much to it. Minimalist Facebook simplifies the Facebook interface so there's less unwanted crap on the page. Here are a couple of before and after shots to give you an idea of the stuff it removes: