In my view, a good idea is generally the merging of one or more crappy ideas and so-so ideas into something that's workable. Because of this, I think you need to provide some mechanism for the cream to rise to the top.  For the use case I'm envisioning, sharing ideas with a small number of users, I don't think a traditional voting system would work.<p>I think this could be an interesting space to employ some sort of visualization.  I'm thinking something like <a href="http://www.archimuse.com/mw2006/papers/lowndes/lowndes-fig2-400px.gif" rel="nofollow">http://www.archimuse.com/mw2006/papers/lowndes/lowndes-fig2-...</a> for ideas.<p>Technically, I'd want something like this to be real time, shouldn't be too hard with ajax.  There would also probably need to be supporting collaboration features, like chat.