Also a Facebook addict. Great way to leave notes for my close friends so that they can answer at their convenience.
And sure, real friends should already have you phone number, etc. But life seems to happen this way: you get out of school and are so wrapped up in starting a career, finding a spouse, kids, etc., that it is so easy to lose touch with people. I had some wonderful friends in college who I lost touch with and recently found through Facebook. One of them, she was my BEST friend for a while, I literally jumped for joy when I found her!
I also ignore the snowballs, flair, etc. Do the senders find out if you ignore? I don't want to offend anyone, I just don't get it (or care to).