I won't say it does a great job, but Facebook does allow you to categorize your friends by "close" vs" acquaintance" vs "alum" and so on. It's worked pretty wel

I won't say it does a great job, but Facebook does allow you to categorize your friends by "close" vs" acquaintance" vs "alum" and so on. It's worked pretty well for me insofar that I get notifications whenever a close friend updates and when I want to share with everyone-but-X. Not so good as a subject matter filter though. I can create a list of only tech people on FB, but if a tech friend wants to post about his puppy to everyone, not so much I can do about that.