I realize you prefer not to use other people's work around here but I'm about to make a really strong case for it. I'm sure you've been to the StackExchange forums, right? You know how you get new powers based on reputation, as well as the ability to vote up and down answers based on quality, yes? That'd sure be nice around here.
I mean, you could write it yourself - but it's only a plugin away in a pinch.