Representative democracies were invented to solve the "junk food policy" (i.e., passing out all of the money in the treasury) problem of direct democracy. Maybe there could be a representative link aggregator where annual elections determined who was allowed to vote on links.

A variation on representative democracy would be to have a recommender system identify demographics, and then to weight each demographic equally. So, for example, the votes from the "blogspam fan" demographic would be normalized to one, to fairly compete for representation with the much smaller "long thinkpiece fan" demographic.

Another solution would be quadratic voting, where you can vote once for free, but the nth vote would cost (n-1)^2 reputation points. That would allow established community members to express their intense dislike of certain content, to balance out the larger population's mild preferences.

It would be pretty cool if there was Reddit, but each subreddit could implement a different voting system. We might see a lot of progress and experimentation.