Actually, the social graph is directed - like, say, twitter. So I can explicitly follow people I know have a penchant for picking up decent new music first.

This might be the "muso" in your real-world social group or it might be a respected journalist outside that group. It might even be Bono himself.

I'm in a similar age bracket, and I've had "so what are you listening to these days" conversations with friends. I find them quite rewarding, even though my broader tastes have settled down.

I'm biased (obviously) but I think we've built something along the lines of those conversations - and more (check-out maps!).