I've mixed feelings about social networking sites - they can waste a lot of time, yet for a writer they are attractive. When much of your working life is spent alone, staring at a screen or scribbling edits on sheets of paper, there's something reassuring about being able to contact a wider network at the click of a mouse. I mostly use networks specific to my activities - two for writers ( Litopia and Bloggers With Book Deals ) and one for science types ( Nature Network ). Just like the watercooler moment in a normal workplace, these naturally bring together people with work in common, who can moan to each other about the latest problem, as well as discuss last night's hot TV. But I do also have a Facebook page, which I use less often, but like for its immediacy and the way it puts me back in touch with old friends and colleagues. Yesterday I clicked on the 'people you might know' link in Facebook, and amongst the people with obvious links and those I've never h...