I threw together a quick tip that I posted to MSD2D about how to integrate user presence information into web parts. I saw a couple of the stock Microsoft parts doing this and thought it would be good to use for some of our web parts since we also take advantage of the Live Communications Server internally. One good application of this: I wrote a web part that displays a list of the current WSS site administrators (so users know who to contact to get more than just reader permissions) and threw their presence info in there so if someone wanted to request permissions or ask a question, it was right there for them.
I’m thinking I should put together a series of articles talking about how to build that “list site admins” web part. It’s actually not as easy as you might think, since you have to run the part as an administrator rather than as the currently logged in user, and then it gets trickier still if you try to use the same web part on a WSS site that resides underneath a SharePoint Portal Server “My Site” (because of the way administrators are set up there).