For the security conscious, there are GPG keys available for my main and GMail addresses. (I don't use them for actual e-mail much, mainly for signing source code checkins.)
If you aren't using jabber, please consider switching - it is superior to MSN in pretty much every way.
I have a micro-blog called ~jynxzero, where I post random links, quotes and pictures that take my fancy
You can check out my music taste on last.fm. Feel free to add me to your friends, but I don't interact with people a lot on there
I like taking photos
I have an account on del.icio.us, which I use to organise the web. You can check out my links or point out interesting sites to me.
I have a Facebook profile, although it is "friends only", and I generally only accept requests from people I know (and like).
I'm on LinkedIn, although, seriously, what is the point? :)
I occasionally update a LiveJournal. Mostly to organise my own thoughts and memories. It's for close personal friends only.