Lately there is much rumor about the (patented) hashgraph consensus algorithm, which claims to have very good complexity measures. See the whitepaper:
https://swirlds.com/downloads/SWIRLDS-TR-2016-01.pdf
A central part of this appoach, is the so called "gossip about gossip" which uses a gossip protocol to spred the gossip history itself through the network. At least, if I'm not mistaken. This builds a data structure called the hashgraph.
On top of this, then runs a Byzantine fault tollerance algorithm, but that is of no concern for this question, which is:
Is the hashgraph-algorithm really the first who uses such a data structure, to gossip about gossip, or are there previous/other approaches, too? Couldn't find anything, though.
Edit: I have problems finding the right Tags. Maybe someone could elaborate on this?