Bitbucket - Public hosting of any code I think might be of interest to others.
Github - I used to be primarily a Mercurial user, whilst I do tend to favour Git more these days through force of habit I mostly use Bitbucket for hosting and Github for watching other peoples projects.
LinkedIn - My profile on LinkedIn, probably covers it.
Stackoverflow - I am a bit of a late comer to this site, but better late than never.
Code Project - A programming community centered around Microsoft technologies.