Poke, tweet, update, get a life! Stop wasting your time messing with people who spend way too much time on these things. If people you know are updating you about their lives once a day or more, have them email you or give you a phone call. People who spend all their time with their faces buried in social networking sites are LOSERS.
Once you've found all your old friends, tweeted every waking minute of your life, and updated all your 1st level connections on your latest brilliant scheme, go do something important--like your job, clean your house, or feed your kids. Social networking is an oxymoron for morons. There's nothing social about it. It's fun for the first 5 minutes but when it really comes down to it: Nobody cares.
Get on a reality TV show if you think your life is all that fascinating.
Social networking is the web's version of the old unix .project file where you could find out little tidbits about people by fingering their username@host. Yeah, it was dumb then and it's still pretty dumb.
Social networking, I predict, will be the next embarrassing legacy from this generation. Stop doing your loser management. Leave it behind folks--get a blog and get a life.