This is going to become one of the big battlegrounds of office etiquette, and there’s no universal answer to it. We spend a lot of our time at work, so it’s only natural that we’ll make a lot of friends there, as well as a lot of acquaintances that we politely pretend are friends, whilst not really involving them in our personal lives outside work.
Social networking sites blur the lines between our work lives and personal lives, but also between our personal lives at work, and our personal lives outside work. You could be quite happy discussing what you got up to on a hen or stag night, for example, with your friends outside work, but find that if you include your friends at work, the office gossip mill means that everyone knows by lunchtime.
Before you start making social network connections with people at work, stop and consider what you’re going to end up letting them into. It might be safest to allow some people into a limited profile, and save the really juicy details for people you know you can trust.
Also consider using the options in whatever social network service you use to hide private details from the public. Otherwise co-workers who you don’t want in your close circle of friends could still be browsing your information, via links from the friends lists of others who work with you.
But in the end, social networking sites are all about putting yourself out there to be found by other people. If you’re worried about the implications of this, you maybe shouldn’t be getting involved.