A recent study reports that Facebook users who upload flattering photos of themselves and have a ton of "friends" are really just narcissistic. Well, it's a little more complicated; the researchers can suggest that the social-networking website can be used as a tool to detect narcissism in the people who use it.
As for the signs that you're a little too into yourself: Posting flattering photos as your profile pic — who doesn't?!; and maintaining a large stable of Facebook friends — I'm over it, since I used to add anyone and everyone in my MySpace days.
Also interesting is that social networks are more popular among narcissists, even though I surmise that many people of a certain age are on Facebook because their friends are on it. Another thing that got me thinking was the importance the researchers put on how people express themselves online; my opinions have certainly changed because of someone's MySpace or Facebook page. What do you think?