Was thinking… wouldn’t it be kind of interesting if there were an attention aggregator for your friending behavior? I mean, being able to see who you’ve friended at many social networks and then inferring other folks you might want to meet would be pretty useful — and as we tend to say — would accelerate serendipity.
And this would go beyond simple XFNing someone — this would actual include identifying and measuring your behavior with and towards each friend over time… for example, do you message them often? Do you recommend links? Who do you always invite or add first?
Anyway, I think I’d like to be able to get friend recommendations and make new connections — kind of like an accelerated LinkedIn… oh well, maybe that’s just me.
Factory Joe 
i always hoped that share.opml.org would go that way. who do you read often? who do you comment on often? what else have other people tagged open+source?, etc.
Serendipity made me think of Goombah.com. It’s a download but totally worth it. It matches you with the top 20 people that share your music taste. Also great recommendations and free tracks. They read your mind.