Brizzly's even better provides a clean, simple, ad-free interface for Facebook. Twitter, too.
Getting started with this free Web service is a snap. Sign up for an account, then supply your username and password for Facebook and/or Twitter. You'll have to click through a couple "approval" pop-ups, which is normal for any outside service seeking access to your account.
Now you've got a simple front end for your Facebook news feed. You can update your status, "like" and comment on friends' posts, watched posted videos, write on walls, and so on. You don't get every single Facebook feature--you can't "hide" a friend or play any games--but you do get a refreshingly streamlined interface.
You can find out more about Brizzly (which is even more robust as a Twitter surrogate) in this video.
As someone who uses Facebook primarily for reading friends' feeds and posting the occasional status update, I'm seriously loving Brizzly.