There's a bit of fun going on at elgg as they have released Explode that lets you link with friends. I blogged about it here (includes screenshot) or you can join up by clicking on this logog
Neat! Sounds like what I wish Moodle had. Since Moodle is often used in parallel with Elgg, there should be a way to bring everything together. (BTW, MySpace demography is apparently older than what one might expect.)
What is so good about it is that the explode presence is lightweight, being mainly in a piece of code embedded in your own web page or blog (thereby increasing traffic to that also). This means that friends can link via blogs or home pages wherever they are, with the conversation being on 'comment walls'.