Very cool. I remember back at Caltech when Adam D'Angelo wasn't a Quora founder and was just a hacker dude he made buddy zoo and it had these awesome social graphs. I think this was ported into the early version of facebook and didn't really end up doing that much because the graphs were very simple. Now that social networks have an older audience with a more complex social graph I think this type of stuff could be really useful (especially if you could create FB or other groups from it).