Seriously ... Skip Some Photo Ops.
Be careful of the pictures you post on Facebook. You might want to initially shrug it off -- "Eh, just my friends are going to see it, right?" -- but consider this: EVERYONE is now granted access to Facebook -- this means parents, employers, coworkers, and so forth.
Risque pictures of you on Facebook can prove to be a problem if some of these people have access to your profile. If you still have a great need to post these pictures, then at the very least block your profile (you can find this in your privacy settings), so that you have to approve a person before he or she can see your profile.
That way, you won't put yourself to lose friends, respect or worse ... your job.
I only recently noticed all the privacy settings you can send, so yes, good idea! You can also only allow certain people to see your Wall, which could be on the receiving end of inappropriateness too!