Google+ was ahead of it's time.
Discussion
Wave, too.
Would be cool to be able to lock notes to given npubs.
And not just posting to a community relay; actually having 'circles' that you define on nostr.
Nostr+
What if the entire circle and all the event kinds associated with it were exchanged over something like a NIP 29 channel. Basically a private nostr
A circle of jerks