Touch Facebook is a wrapper application, which uses the touch enabled version of Facebook's mobile site. While you could bookmark the site in Internet Explorer (as I have), wrapping it in an application has a number of advantages.
The main one is a dedicated menu bar. A quick tap in the Touch Facebook app, and you have options to jump to the Facebook homepage, your profile, Facebook Chat, or to post a status update, as well as all your Facebook settings. You also have app showing up in the task switcher for quick access.
It's a different way of looking at Facebook, and you loose all the Windows Phone UI styling in place of a long 'ribbon' approach to the content, but this may be suited to how you use Facebook.
Touch Facebook is a free app, so there's no harm in trying it out and seeing if it works for you. You can find it on our App Directory.