At the time, I noted the way that more and more information that was once delivered by independent web sites was now being delivered directly by search engines, and that rather than linking out to others, there were strong signs of a trend towards keeping the link flow to themselves.

Is Linking to Yourself the Future of the Web? - O'Reilly Radar

I may exist in a bubble¹ but it seems to me that an opposing tension is emerging. Twitter has been used² by many people as a search and question answering service, as has FriendFeed more recently. Aparently people find things like Digg useful too³. By their nature, the organic links in these serves are mostly external, though of course both services are somewhat limited by the number of followers someone has.

1. Yes, I exist in a bubble. ↩
2. Yes, when it worked, fine. ↩
3. Though for the life of me, I cannot work out why. ↩