How'd I do that?

There are a number of sites that offer methods to add your messenger status to your website or blog. There are the official Yahoo & AIM status indicators. (they're HTML code you can paste into your web page or blog template)

Personally, I had trouble with the AIM status icons when using Trillian.
They're also large and clunky!

I also found the online status indicator which has MSN, IRC, ICQ, Jabber, AIM and Yahoo.