Since Google Sites doesn't allow public user comments, I've decided to get a blog and embed the frame inside the website. If I decide I don't like it, I can always change back. Or, you know, Google could allow user comments that aren't just for owners and collaborators of the website... but if they haven't done it by now, I'm not sure they will.
In any case, now you can actually give me feedback on my website in my website... sort of. Fire away!