To Friend or Not to Friend

I've recently become more and more involved with social networking online (Read: Facebook) and I'm curious as to what other people think about it. Here's the deal:

I use my Facebook as a way to keep in touch with my friends both local and across the planet. Everyone on my friends list is a member of my family or someone that I am actually friends with, and not just some random person who requested to be my "friend" just to pump up their numbers. I don't add people just because they ask me to be friends. I understand that other people don't do the same, and add people willy-nilly and that's all fine and dandy for them. I just prefer not to.

Recently, I've received a lot of contact from people I knew in high school (not necessarily "friends" but we did go to the same school at the same time). Let me digress a little by saying that high school was not the greatest time in my life. It wasn't a horrible experience for me, but it's certainly not one that I ever want to go through again. I was awkward and shy and smart, and was the butt of a lot of peoples jokes, even when they thought I wasn't aware of it. I had two very close friends who I still keep in touch with today, but the rest of my "friends" were temporary people in my life. I'm a little of the opinion that if our friendship was all that great, we would never have lost touch in the first place. I don't have a wealth of positive memories from that time, so there's a large part of me that would like to forget it existed in the first place. I know that comes from my own lack of self esteem, rather than the fact that they were bad people, because they weren't. But the fact remains that I am very happy now, and I don't really want to open the door that might let some of that doubt in myself come back. Maybe that's just a flaw of mine, but I can't pretend it doesn't exist.

So I've chosen not to add people that I went to high school with just because I went to school with them. If it's someone who I recognize and want to communicate with, then I'll send them a message saying the usual Hi, How are you? What's up? kind of stuff. But I won't automatically add them. If we get to chatting back and forth via e-mail, then I'll add them to my friends, because I feel like we've actually started establishing a relationship again. If that ends, well then I'll take them off my list. There are some that I won't even bother messaging because I simply have no desire to start a relationship with them again. Maybe that's mean or petty, but it works for me and keeps balance in my world.

So I'm curious what other people do. You don't have to participate with Facebook to answer this question either. What do you do if someone you haven't spoken with in a long while randomly sends you an e-mail, and maybe you weren't all that fond of the person in the past? Do you respond? Do you ignore them and hope they go away?