Twitter (@AllanDouglasDgn) and Facebook are my primary hang-outs, but I also have G+, LinkedIn, Goodreads, and Triberr accounts. Facebook has a page for my book (http://www.facebook.com/pages/Writing-for-Profit-or-Pleasure/143704772350971) and my personal page, but i don't promote the personal page and I only "friend" people I'm genuinely interested in hearing from. Twitter is my primary outlet for professional communications.
Beyond The Margins at http://beyondthemargins.com/
I use LinkedIn, Facebook, Twitter and a few other sites to interact with friends. The main site is Hubpages where the writing community is awesome.
I frequent Facebook, Linked-In and various blogs. My friends and colleagues on these sites are eager to share and have priceless knowledge and experience to share. There are always some kooks and haters, but they are easy to spot and to ignore.
Usually just blotspot.com
Facebook, twitter and tumblr.
Jade Sperry (jadedphotography.me)
I frequent the following sites of music news blogs and band sites daily:
I post articles on my own blogs and also on Facebook, Twitter and LinkedIn.
Society of children's book writers and illustrators, Jacket Flap, Face Book and Twitter.
Twitter. Facebook. Diktkammeret, where I am the teacher.
I keep my followers up to date on Google+ (https://plus.google.com/communities/112121115940665281551), Twitter, Facebook, LinkedIn and Tumblr.
I am active on Facebook and Twitter and Google Plus and via them get into discussions on forums etc
I sneak time in on Twitter and Facebook. I follow and interact with other authors that I admire, which keeps me thinking as an author. I also follow author blogs and pay attention to what others do to get through the process of completing a written work.
Livejournal and Facebook, but mostly I utilize my huge network of online friends via email or chat or text. Twitter tends to take up too much of my time and I have to stay away from Tumblr. I would spend my life looking at pretty pictures.