We can run our own servers, curate our own sources of information, and build reputation networks, in spite of the overall trends. The key difference is to do it for any reason other than profit.
Another weakness of the evolved systems is the whole "Up/Down" voting system that happens everywhere. When you force everything into that single dimension, you waste almost all information that can be gleaned from someone who has just spent their attention on something. I think that we need to have systems that can vote with vectors. Something can be funny, technically wrong, and insightful all at the same time... wouldn't it be nice to be able to learn those things?
Also, a pet peeve - HTML doesn't allow the Markup of Hypertext. It actively works against the idea of a Memex, a thing we still don't have 80 years later. 8(