was just talking about this on HN the other day: <a href="http://news.ycombinator.com/item?id=1691492" rel="nofollow">http://news.ycombinator.com/item?id=1691492</a><p>it's clear that contextual sharing is the feature of social networking, but I underestimated facebook's ability to implement such a drastic feature so elegantly (and quickly)