A story about Facebook shutting down various political sites (that shouldn't have wanted to be on there in the first place) got me motivated to finally start blocking Facebook cookies and plugins that hit my browser as I surf around.
It's not enough to just not be on Facebook -- would like to be free of its slime trail.
Am trying out a plugin called Ghostery that selectively blocks trackers but also gives you a list (if you want it) of all the various third party presences on the sites you visit.
One of the items I'm now blocking is called Facebook Exchange -- this Wired article makes it sound about as creepy as you'd expect.
(According to Ghostery that Wired page is Facebook plugin- and cookie-free.)