It would be nice with voting (both up and down) if there was a comment part - yes, it's always nice to be upvoted and always a little disheartening to be downvoted but in both cases sometimes it's nice to know why it's been voted a certain way.

This is definitely true of downvoting. Okay, so if you've but an obviously flame-baiting post up then the reason for the downvoting is pretty apparent; but sometimes you express an opinion, or attempt to post an answer and you get downvoted... but you don't know why. It's fair enough that someone thinks that what you say is wrong or is flawed in some way, but unless they back it up with a reply to your post, how are you going to know where you went wrong?

We learn from our mistakes; but if they're not pointed out, how can we do that? I know that sometimes I'm wrong (maybe because my knowledge has a holes where I don't expect them or because I maybe replied too fast and missed something or maybe just because I'm plain wrong) but I for one would like someone to actually point out where I was wrong - not just anonymously downvote me. Show me and I shall learn.

Even with up-voting it would be nice sometimes to know why someone thinks your post / reply is good. Perhaps this doesn't have as much value as identifying your mistakes, but nice nonetheless.

Still, all that said, the voting system does work quite nicely given it's simplicity and certainly gives the incentive to want to contribute to the community and makes you feel more part of it.