For a while at the end of 2007, this blog had a feature where it showed presence information for me (with the ability to send me an IM) based on my status in Windows Live Messenger. I’ve removed that functionality now because: a) I find IM to be a distraction and so am very rarely logged in; b) I use a private IM system using OCS when I’m working; and c) I use a variety of IM systems (and three different Windows Live logins), so my presence on any one Windows Live Messenger account is not really relevant.
Even so, if this is something that might be useful, there is a page on Windows Live to generate the necessary HTML (I found this information from Michael Niehaus’ blog).