This thread is interesting to me because we are contemplating using this software to start up another type of community.

Why not do away with the -- voting all together and just leave the ++. If a node does not recieve any ++ votes, isn't that the same as a -- vote without the negative connotation and also prevents ganging up on someone because of who they are?

There are so many other issues with running a community that is vibrant and informative, but minimizing SPAM,TROLLING,FLAMING, ETC. is a very important consideration in not only the value of the site, but also in the time needed to maintain it.