The topic of profile pictures is one often talked about around our cubes here at work, especially Twitter avatars. They're so small (so mysterious) that what a person looks like on Twitter is often very different from what they look like in real life. In some cases it's a good thing, in others it's not so good.
I know this is shallow, but I'm willing to bet a few bucks that many of the little square pictures that end up online take a whole lot of time to create. Of course, I won't name names.
I think a new Samsung ad does the topic justice. The ad hawks a new point-and-shoot that makes self-portraits a cinch because it has an LCD screen in front of the camera.