Definitions of knowledge:
The state of knowing.
Familiarity, awareness or understanding gained through experience of study.
The sum or range of what has been perceived, discovered or learned.
Learning.
Specific information about something.
Carnal knowledge.
So... It's about learning and gaining an awareness of information through the experience of yourself or others. What you know is a large part of what defines you. I like 'The State of Knowing' as a name for a group or event actually, has a nice ring to it.
Initial Thoughts:
This does seem tricky if I'm perfectly honest. I guess existing solutions would include things like:
Wikipedia which allows a platform for people to share information on pretty much any subject known to man, they've done this pretty well though and have got that web base pretty much on lock down.
Facebook & Twitter allow people to share information freely amongst each other but obviously this is far from it's focus.
Databases that are free to access online, google books with page previews.
This is the 'free' knowledge route, I guess that's a more obvious way to go. Maybe I need to focus more on the question of HOW do you get people to give more knowledge. What would make people share their intellect on a more regular basis?