Before Pinboard.in, Del.icio.us, and StumbleUpon, there was a community of voracious link-archivers and sharers called Feed Me Links.
Feed Me Links is a niche but thriving social bookmarking community. Having launched in 2002, we predated the social web we now take for granted. Think for a second: no rss feeds, no Like buttons, no endlessly scrolling feeds, no round avatars.
At the time, everyone just used browser bookmarking, and the idea of hosting your bookmarks online, let alone "open-sourcing" them to make them fully visible le to everyone, did not exist. Yet I got 15,000 people to sign up and share their links anyway :)
Feed Me Links (feedmelinks.com) is an early social-bookmarking site used primarily by hackers, designers, musicians, and artists. Since I no longer have time to work on it, this page is basically a really elaborate 404 page :) Why not read the Feed Me Links Crunchbase entry.