There are lots of apps out there that give you quick access to many different services including Facebook and Twitter. Head for Facebook gives you instant access to your Facebook account directly from your desktop on your Mac. The cool thing about Head for Facebook is that it actually looks good, doesn't get in your way, and actually works great.
A lot of times when I test out Facebook and Twitter ports for Mac, or even the iPad before there was a native Facebook client, a lot of the features were broken or just plain didn't work. Typically they were crash havens. That isn't the case with Head for Facebook. In the week or so that I've been using it, I haven't experienced one crash or one dead link. I'm also enjoying how quickly I can access it and then tuck it away.
If you use Facebook for iPhone, you'll most likely be familiar with how chat bubbles now show as little circles until you flick them away. Head for Facebook uses the same style bubble to dock itself to your desktop. In order to access Facebook, just click on your bubble. You can choose between blurring and darkening your desktop background when you have Head for Facebook open within preferences. I personally prefer the blur effect.
As far as settings go, there isn't too much to fiddle with but along the bottom of Head for Facebook you'll notice some settings. Here you can change the transparency of Head for Facebook as well as toggle between mobile and desktop views. Both render quite well. I prefer the desktop version since it pretty much shows me exactly what I get when I log in to Facebook.com and gives me the exact same feature set.
If you're looking for the complete Facebook browser experience on your Mac without ever having to actually open a browser, Head for Facebook is it. I am typically not a fan of plugins or ports that sit on my desktop but the way Head for Facebook is designed makes it unobtrusive but convenient at the same time.