I have a frankly ridiculous number of online presences (full list here), but here are the best ways of keeping tabs on me:
You should definitely subscribe to my ‘Rich Text’ newsletter. It is short, perfectly formed, and not at all spammy. I tend to send out about one newsletter per month.
Please follow my Facebook page. I post links to most of my new writing there, along with the occasional photograph. I typically only post one or two updates a week.
I am @friendsofdarwin on Twitter. I tweet a mix of personal updates, history of science stuff (mainly of a Darwinian nature), and anything else that interests or amuses me.
I post to my Instagram photos feed roughly once a day. I tend to publish a mix of serious photos and fun snaps.
My Flickr page contains thousands of photos going back many years. I tend to post to it in batches, usually after going out for walks.