Some recent examples in particular stand out, because they involve people who (as far as I know) have never met in real life.
- nafe and lifecollage, about the library at Skywalker Ranch
- madbodger and julianyap, on reference sources for the banning of marriage by the early Christian church
- eeyorecol and skreeky, on mixed (baseball) marriages
- coraline and holmes_iv, about Wagner's Lohengrin.
I think I'm so pleased about this because one of the things I've always liked about throwing parties is putting people from the many disparate social groups in my life together. But large parties are problematic in many ways. Even when they work well, it's by no means assured that the people who would have things to say to each other will actually meet. Moreover, LJ is better at this than I could ever be, even if I carefully picked guests for a small party, because people will end up commenting on things I had little if any idea they were interested in.
Well! I suppose I've found the second reason for my LiveJournal's existence.