Long before I heard about cryptocurrency, I heard about complementary currency...
It was probably in 2001-2 and probably from promotion of this (now out-of-print) book The Future of Money wikipedia 
Here's a paper from 2003 which mentions most of the things I remember being excited about for complementary currency: Complementary Currencies in Japan Today:
History, Originality and Relevance pdf
YOUTUBE dkx6tC5p9l4 2015 interview with Bernard Lietaer touches briefly on bitcoin
When I first heard about bitcoin, I was expecting or hoping to see an explosion of copy-cats deployed in the world as complementary currencies. I try to imagine how all of the sophistication we have for financial modeling and accounting could be applied to other problems by introducing complementary currency and decentralization.
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I raised the question today in TechFriends #blockchain channel... to what degree does crypto currency community know about complementary currency. Collected these thoughts and links before returning to work.
And this evening learned that complementary currency showed up in the #fedwiki chatroom just yesterday: Why the World Needs People Powered Money medium