I've posted a link earlier about 'Scuttlebutt' (and the actual client on top of it, Patchwork), which is kind of a decentralized Facebook.

It's main innovation, as far as I can tell, is that it uses the real world as a model for its approach. Your content spreads as 'gossip', peer to peer (over LAN/wifi), but also propagates through 'pubs' that are internet-accessible.

What first made me interested is that the Patchwork client is quite user-friendly and I've noticed that the relatively small group of current users are not all tech-savvy. That's something of an achievement. Furthermore, some other options I've looked into strike me as either unrealistically decentralized, or too (pragmatically?) centralized.

Anyways, even as just as a look into how thing could work different I can highly recommend checking out these types of alternatives!