I still like the posts idea, but bleh.
If we're gonna vote users, can we make it, say, between +3 and -3? So if a person is generally good we can vote +1, and if they're really exceptionally good in difficult circumstances we can vote +2/+3? Just an idea.
Guido and I are discussing it on Messenger, so I may post back with more stuff.
Edit: yes, I think Guido's implementation is very nice too.
I did tell him on Messenger and forgot to post my approval here.
I think we've also decided that comments should be optional... for reasons that I'll explain later if I can find a good way of explaining them.