This is a bandwaggon I'd hoped never to have to jump onto, but just in case -- here are links to my profile pages on other websites:
ThemisAthena on Leafmarks
Themis-Athena on Goodreads
Themis-Athena on Libib
ThemisAthena on FictFact
Lioness at Large on Wordpress
ThemisAthena on Pinterest
Ulrike on LinkedIn
Ulrike on Facebook
Essentially my handle is the same on all sites except for LinkedIn, Facebook and Wordpress; just note that sometimes it's hyphenated and sometimes it isn't, depending on the respective site's user name parameters.
ETA1: My Wordpress blog -- Lioness at Large -- is now operational, too. Currently I'm still mainly copying my reviews there just to have an additional home for them, but I think from here on out I'll be blogging on WP as well.
The only other sites (besides BookLikes) where I've so far actually interacted with others are Leafmarks and Facebook.
ETA2: Well, duh. Bookstooge just shared Leafmarks's announcement that the site will be shutting down as of July 1. There goes yet another option then ...
So that leaves Facebook as the only other site where I am truly active. Time to start experimenting with the others for real, I supose.
FWIW, up to now, this has been my stance vis-à-vis my accounts on the other sites, respectively (and to the extent not expressly struck, the following is still true):
Libib and Fictfact to me are merely (as yet incomplete) backup book catalogues.
Pinterest is my "everything but the kitchen sink" meme repository.
Wordpress is not much more more than an ID and a blog devoid of even the first post at the moment, so as to be able to follow other people's blogs (on WP and elsewhere). Depending on how things go on here, this may or may not change.
It has changed.
LinkedIn is another "just in case" account.
Goodreads, finally, is also merely a temporary expedient. I pulled out of there in 2013 and have no intention to go back for good -- just using my vestige ID as a fall back option in the current situation.