I can’t profess to spending as much time as Jo considering personal brands and the like, but it is something that interests me – marketing is part of my library role and something I feel I could be much better at.
As suggested, I tried Googling myself. Both my forename and (married) surname are very unusual, so my full name is nearly unique, which can be both a blessing and a curse! The results are the same whether or not I’m logged in to Google: 9 of the first 10 results are me. They’re mostly things I’m happy to see there (LinkedIn top, with Twitter high up and a journal article I wrote several years ago close behind). The page about me on my wedding website is second (a tribute to my husband’s excellent HTML-writing skills), and weirdly my profile on an environmental community site which I barely use is also highly ranked!
My blog isn’t there, which doesn’t surprise me as I felt funny about putting my full name on it for a while. I’m over that now, but I do think I consider this issue more than most due to my unusual name. I still often use Edith S (e.g. on Twitter, blogs and Google+) to be a little less easy to find, but perhaps I’m being needlessly paranoid. To my surprise 192.com claims to know 4 Edith Spellers in the UK, none of whom is me, so there’s at least four more around than I realised!
Incidentally I tried searching for myself in Bing as well. I preferred the Google results, but on the plus side Bing alerted me to something I didn’t really want to be public (a wishlist I’d made for myself of possible home furnishing purchases) so I’ve sorted that out now.
To consider Jo’s aspects of a personal brand in turn:
Name used
I’m not consistent with my ID across different platforms. Weelassie used to be my standard username so I have that on Delicious and a few other sites, but when it came to Twitter that was taken so I ended up as Wiilassie. I think that name implies that I’m a) Scottish, b) female and c) like Nintendo – all true but not important aspects of my professional persona! I’ve previously considered the upheaval of changing Twitter username but can’t think of a new one I like. Espeller, multifacet and multifaceted are taken but frustratingly dormant; edith and ediths are taken by Dutch Ediths; edithspeller is available but too long? My blog title, Multi-faceted, is different again. I like the name which I chose because a) I wanted to write about several facets of librarianship, and b) I’m a fan of Ranganathan’s facets :)
What do you think about wiilassie as a username? Does my lack of consistency matter?
Photograph
My standard avatar at present is a photo that’s approx 2 years old, and is very close-up on my face. My glasses are prominent and, having worn specs since I was 5, they’re a big bit of my persona. Maybe it’s a bit intimidatingly close-up though?

On Twitter I changed my avatar six months ago to a sunset photo I’d taken: I like it because it’s tranquil, but it doesn’t help people recognise me which the previous avatar did. I’m not a fan of changing avatar all the time because it weakens people’s recognition of you.

Another avatar which I use sometimes (e.g. on my blog and blog comments) is me with a librarian t-shirt and a magnifying glass, taken at a fancy dress party many years ago. I really ought to retire that one!

Professional/personal identity
I take a similar view to Jo, that it’s impossible to maintain a purely professional persona online unless you maintain two (or more) profiles, something which I don’t think is worthwhile and is anyway prone to error. Something I do struggle with is how much of my personal life/views to expose on public sites, e.g. Twitter. Things like political views can be quite controversial but are part of me and not something I want to hide. I’ve been formulating a blog post on this in my head for a while, so more may follow…
Visual brand
I don’t think I have a visual brand. I like purple and blue, hence the blog colour scheme (when setting the blog up a couple of years ago, I chose a template which allowed custom colours), and I use a default scheme on Twitter (though I think people only look at that when first deciding to add me). Maybe something I should think about, especially if I do ever produce my own business cards. My organisation used to provide business cards but no longer, and I had to throw my old ones away after the institution rebranded and retitled itself, changing my email address in the process!