Any site which I don't use... ie I don't think any of it is essentially narcissistic, though obviously all of them can be. Surely a blog at least contains the assumption that one's writing things worth reading, which might be self-delusion, whereas a Facebook profile could just be about keeping in touch with some people more easily?

It rather depends on the content and purpose, doesn't it? And how one uses it ... I mean, I have LJ friends who post stuff that sometimes comes off as "hey, look at me, look at me!" -- but I know a good many of my posts must come off that way, too. But I read those posts and comment on them, because I see it as communicating with my friends. And I write those things for the people who are people I consider my friends. So in that sense, it's like a big group asynchronous phone call. My blog, as you know, is a bit different. My Facebook is deliberately about ME - but as a public face of my private self, if that makes sense, because I put it up initially because faculty were encouraged to do so, and I have 6 students who watch my facebook.

no online presence or site in inherently narcissitic. It's all in how you use it.

Also: might your last comment be related to the (WASPy Puritanical) notion that a lady's name should appear in print only 3 times in her life (birth, marriage, and death)? Which itself goes back to the Habermasian notion of the bourgeois creation of private vs. public space in the 17th century...?

I'm going for a personal homepage, by which I assume you mean a page all about the author, their hobbies, holidays, 'artistic' output, etc. This is because, unlike the other named options, it works on the assumption that a person will come to that page purely to read all about its author. Whereas, as other commenters have said, MySpace, Facebook and blogs all involve communal / mutual social interaction as well as personal narcissism.

I think it all depends on how it's used.

I'm not sure exactly what it means, or how it relates to your question, but it's very hard to imagine using Facebook (or MySpace, I guess, though I've never been there) for teaching in any practical way. I find Facebook shallow and superficial, which is why I have no problem friending students there, but don't encourage them in here. A colleague and I were having this conversation, and he said that he doesn't like Facebook because it gives him TMI about his students (getting drunk and throwing up and so on). But it does, as someone has said wisely, depend on how you use it. It just seems that FB is used MORE for the "in your face" extreme of public behavior. I personally don't post that kind of "out there" information on it, but a lot of people do. Thus, QED - it's more narcissistic, at least for those who use it that way??
Bleah, I think I'm talking in circles - too early and after a night of insomnia...