There's an interesting paper by Will Davies, called Is Online Community a Policy Tool?, which is part of the IPPR's Digital Manifesto initiative. It's a thought-provoking look at trust, online interaction, and the potential role of government (or use of therein).
The issues of trust, authority and rating are interesting ones in this context. On the Global Ideas Bank we use ratings, but this only rates the idea rather than the idea author. We also keep track of the number of ideas by each individual, but quantity does not necessarily equal quality...perhaps we could calculate an average idea rating from those who have submitted more than five ideas, to give an idea of their 'quality' as judged by the GIB audience.
Certainly, as we move more and more towards becoming a functioning online democratic think-tank (as shown by our recent brainstorm which led to hundreds of ideas flooding in within a set time limit), we will have to look closely at our processes of selection and judgement. Part of this we have done by adding in different rating categories (feasibility, originality, humour) which enable the differentiation of ideas that people think could genuinely be put into practice...but perhaps some sort of authority needs to be given to the social inventor or idea author themselves.
It is these issues of providing an appropriate community space which is open and democratic, but also needs rules and codes of agreement, which are discussed in the paper above. Similarly, it looks at the translation of online interaction to the real-world, which is another problem the GIB has to face: what are the best ways in which we can a) encourage people to implement their own ideas where possible and b) package and communicate themed ideas to those individuals and organisations in such a way that they are listened to......somehow, the suggestion that we should big up Politicians who promise to promote the top 10 ideas isn't going to cut it.