Facebook has begun rolling out an important new protection, and Gawker's Ryan Tate says users should "jump on this" as soon they can. It's an encryption tool called Facebook HTTPS that will "keep any random jerk in the café from hijacking your account." Unfortunately, users have to opt-in to the service, at least for now, and Tate offers a walk-through of how to do it under Account Settings. (Facebook does, too, in its blog post.)
You may not be able to make the switch immediately, but keep checking back. "Switching to HTTPS is important because a browser extension called Firesheep has made it especially easy for anyone sharing your open wireless network—at cafe or conference, for example—to sniff your credentials and freely access your account," writes Tate. Also note that this protection doesn't apply to the Facebook iPhone app.