I think we need to double down on creating a permanent knowledgebase out of the ideas that flow through Socialcast.
I personally like the idea of using Evernote because each person with the shared notebook would have their own complete local copy of our notes.
For those who have not used Evernote - it is a notepad that allows for sharing notebooks and has a great many mobile clients. I think it has a version for every mobile platform as well as the web and desktop (both Mac and Windows).
You can store documents inside Evernote -- PDF files, etc.
You can store links, web pages, etc.
The downside is that it's an unstructured tool -- so adding tags, comments , notes is mostly free form. Upkeep would be more trouble than a rigid knowledgebase.
The upside is that it's cheap --- I think $60 per year --- and individual members could subscribe (or not) on their own without the group having to play accountant to manage sign ups.