Clients need a "follows' follows" feed. Look at your follows' follows, you like what they say or post obviously, and they like what someone posts, you have a higher likelihood of liking it. Scroll it from time to time and add follows as you find stuff you like. This is web of trust like, it's going to be heavy on the fetching but all in all I think a great idea for expanding everyone's social network.

The problem comes with people that follow a thousand other people, you and I and everyone knows, nobody actually sees 90% of their own feed if they follow a thousand people, they're not doing it out of interest. Personally though I try to follow as few people that do that as possible. Even with that, I think it would work rather well, no algorithm or centralized curator required.