Well, I don't think there's a way yet, but here's how I think that would look:

1. First we need to upgrade following to use sets.  Currently you can watch all cards of a certain type, but you should be able to watch all different sets of cards.  This is already on the roadmap (though not yet funded)
2. Then we would just need to make sure we can represent one's friends as a set.  We don't have this yet, because we can't yet define sets by references, but we do expect to keep finding ways to handle more and more set classes like this.  It's largely a question of how to make it work fast enough.

Nice. Makes sense to me. In response to the recent increase in your use of various forms of the word "funding" ;-) We hope to start charging for access to our wagn in September and ought to be able to send some funds your way. At the moment, people around here have been hearing me talk about needing funds t0 help us get to September when we hope our wagn will save us.

  --Peter Kindfield.....Wed Feb 24 10:12:04 -0800 2010

add Sets based on content of relative plus cards

  --John Abbe.....Sat Feb 26 15:50:43 -0800 2011