The other day Nathan Bransford asked about social networks. I've never listed all mine before; let me give it a try (I hope all the links work):
LinkedIn (I didn't realise how much Turkish I had on here!)
Library Thing (all linked at the bottom of this page)
Myspace (hardly ever updated)
Facebook (my author site, Whisky Trench Riders)
Compuserve Books and Writers Community
And NaNoWriMo, in season. If I joined Twitter and what not, I'd never get any writing done!
Which social networks are you on?
Meanwhile, Rachelle Gardner has a detailed round up of advice on How To Market Your Book.
And Indie Book Blowout is coming on 2 September! 99¢ books all weekend!