Not one that's widely used. I made something small where you only see links reposted by friends, so you can get stuff from all over the place, but only if it's

Not one that's widely used. I made something small where you only see links reposted by friends, so you can get stuff from all over the place, but only if it's filtered through a friend. Which is even more granular than Reddit's curation and also obviates the need for community moderators.