Let it be known hereforth that I am not a squasher of dissent.
Here's the thing about having open comments: Don't have them if [and this applies only to people that have comments but complain about them, not those that have comments disabled] you are a) thin-skinned, b) have a problem with people disagreeing with you or c) have an ego the size of Bill O'Reilly's. It's just not going to work out for you. You're better off with an email form so we don't have to be witness to your deleting comments or throwing a hissy fit when someone doesn't think you're the best thing to happen to blogs since...since...whenever.
Regarding this phenomenon of people deleting comments and playing revisionist historian on their sites, I have changed the wording in my own comments to fit what I believe is the true spirit of having an open forum embedded on your personal wesbite.
Then again, my skin is pretty thick, so it works out for me.