Today has been designated by … uh…. Jimmy Kimmel… as the day when you unfriend people from your Facebook friends.
WHY should you do this?
Because you have too many friends, and you miss the statuses of friends you actually care about, because they get lost in a sea of Farmville updates from the kid who sat two rwos behind you in high school biology who you barely talked to anyway, that's why.
Common concerns about unfriending:
Question: Do they know if I unfriend them? (And, do they get a notification that I unfriended them?)
Answer: No. What happens when you unfriend someone on Facebook is that you simply disappear from their friend list (and them from yours). There is no notification given, no email sent. Both of your friend numbers will decrease by one (e.g. decrease from 1009 to 1008).
They might notice that their number of friends has decreased, but unless they go through all their friends to see who is gone, they won't know that it's you specifically.
Question: Will they still be able to see my updates? (And, will I still see their updates?)
Answer: No. You will no longer appear in their newsfeed and they will no longer appear in yours. They won't be able to post on your wall or send you a message (well, depending on how your privacy settings are set, they won't) – nor will you be able to post on their wall or send them a message (again, depending on their privacy settings).
People you unfriend are more likely to notice that you stop appearing in their newsfeed than they are to notice when you actually unfriend them.
Question: Can they try to refriend me after I've unfriended them?
Answer: Yes. They can send another friend request at a later date unless you have blocked them from friending you. However, at that point, you have the choice whether to accept the friend request, ignore it, or block them from friend requesting you.