The hysteria over Facebook's terms of service and what it can do with your content largely ignores the most obvious and important thing:
You and your friends are the ones with the capability to post information about you online, not Facebook. The trail of stuff that you leave behind on Facebook (like the 'random 25 things about me' meme going around at the moment), is left voluntarily. Do you trust your friends not to post embarrassing personal details on your Wall about what you got up to last night? Take a look at most of the archived entries in this blog: the vast majority of privacy issues have nothing to do with Facebook's terms of service. Privacy issues have all happened because people haven't understood how Facebook works. The dynamic of the online world is significantly different than the online world, in that a digital footprint remains and if you don't follow the rules, your content may be seen by people you don't want.
In addition to not opening your heart on to Facebook, use the privacy settings that are provided within Facebook - check out the 10 Privacy Settings Every Facebook User Should Know.